So the issue is still the same as I mentioned at the beginning.
You are still feeding msg.payload true / false back into the drop down. I keep removing this and you keep adding it back in, with more and more unnecessary nodes 
NOTE: If you add a property to a msg (eg enabled), this doesn't remove the existing property of msg.payload. The problem you are seeing is because you send enable property AND payload property in the SAME message, so the drop down reacts to both.
If you send msg.enabled to the dropdown and don't want to change the value displayed, then you need to delete the msg.payload property first.
I have modified you flow to correct this and hopefully you can now see what you need to do
[
{
"id": "c3be85b95be91e89",
"type": "ui_dropdown",
"z": "d0f9a690e04bf3cd",
"name": "",
"label": "REMOTE:",
"tooltip": "Activates Remote-control. Unable to control Pump when OFF",
"place": "",
"group": "4368da8fe6ddbe0c",
"order": 1,
"width": 4,
"height": 1,
"passthru": true,
"multiple": false,
"options": [
{
"label": "ON",
"value": true,
"type": "bool"
},
{
"label": "OFF",
"value": false,
"type": "bool"
}
],
"payload": "",
"topic": "test",
"topicType": "msg",
"className": "",
"x": 505,
"y": 720,
"wires": [
[
"fbdf668d81828a94"
]
]
},
{
"id": "c36f9376d47c9f21",
"type": "change",
"z": "d0f9a690e04bf3cd",
"name": "",
"rules": [
{
"t": "set",
"p": "input_remote",
"pt": "flow",
"to": "payload",
"tot": "msg"
},
{
"t": "set",
"p": "background",
"pt": "msg",
"to": "rgb(255, 51, 51)",
"tot": "str"
}
],
"action": "",
"property": "",
"from": "",
"to": "",
"reg": false,
"x": 810,
"y": 720,
"wires": [
[
"93cdd11b59f438af"
]
]
},
{
"id": "93cdd11b59f438af",
"type": "ui_button",
"z": "d0f9a690e04bf3cd",
"name": "check_remote",
"group": "4368da8fe6ddbe0c",
"order": 2,
"width": 1,
"height": 1,
"passthru": false,
"label": "",
"tooltip": "",
"color": "white",
"bgcolor": "{{background}}",
"className": "",
"icon": "fa-check",
"payload": "",
"payloadType": "str",
"topic": "topic",
"topicType": "msg",
"x": 1030,
"y": 720,
"wires": [
[
"5fab407077ae83a8",
"9c293200e2d4fb91"
]
]
},
{
"id": "4b9452657fcc1d6a",
"type": "change",
"z": "d0f9a690e04bf3cd",
"name": "set drop down value",
"rules": [
{
"t": "set",
"p": "payload",
"pt": "msg",
"to": "input_dosing",
"tot": "flow"
}
],
"action": "",
"property": "",
"from": "",
"to": "",
"reg": false,
"x": 290,
"y": 870,
"wires": [
[
"53c8ef23430cd71a"
]
]
},
{
"id": "53c8ef23430cd71a",
"type": "ui_dropdown",
"z": "d0f9a690e04bf3cd",
"name": "",
"label": "DOSING:",
"tooltip": "Starts or stops the pump",
"place": "",
"group": "4368da8fe6ddbe0c",
"order": 4,
"width": 4,
"height": 1,
"passthru": true,
"multiple": false,
"options": [
{
"label": "START",
"value": true,
"type": "bool"
},
{
"label": "STOP",
"value": false,
"type": "bool"
}
],
"payload": "",
"topic": "topic",
"topicType": "msg",
"className": "",
"x": 510,
"y": 900,
"wires": [
[
"73d7dd197aac9352"
]
]
},
{
"id": "aeac7511c51d451e",
"type": "ui_button",
"z": "d0f9a690e04bf3cd",
"name": "input_dosing",
"group": "4368da8fe6ddbe0c",
"order": 5,
"width": 1,
"height": 1,
"passthru": false,
"label": "",
"tooltip": "",
"color": "white",
"bgcolor": "{{background}}",
"className": "",
"icon": "fa-check",
"payload": "",
"payloadType": "str",
"topic": "topic",
"topicType": "msg",
"x": 1040,
"y": 900,
"wires": [
[
"a41e37df0a74a3b9",
"42a8ebb92f2c7159"
]
]
},
{
"id": "a41e37df0a74a3b9",
"type": "change",
"z": "d0f9a690e04bf3cd",
"name": "",
"rules": [
{
"t": "set",
"p": "payload",
"pt": "msg",
"to": "input_dosing",
"tot": "flow"
}
],
"action": "",
"property": "",
"from": "",
"to": "",
"reg": false,
"x": 1250,
"y": 900,
"wires": [
[
"85aaec73340d36b7"
]
]
},
{
"id": "e84faf494ba5d4d9",
"type": "change",
"z": "d0f9a690e04bf3cd",
"name": "",
"rules": [
{
"t": "set",
"p": "payload",
"pt": "msg",
"to": "readPump.CIM500/ADR_201.ActRemoteAccess",
"tot": "flow"
}
],
"action": "",
"property": "",
"from": "",
"to": "",
"reg": false,
"x": 295,
"y": 720,
"wires": [
[
"c3be85b95be91e89"
]
]
},
{
"id": "fbdf668d81828a94",
"type": "rbe",
"z": "d0f9a690e04bf3cd",
"name": "",
"func": "rbe",
"gap": "",
"start": "",
"inout": "out",
"septopics": true,
"property": "payload",
"topi": "topic",
"x": 655,
"y": 720,
"wires": [
[
"c36f9376d47c9f21"
]
]
},
{
"id": "e21c0a6cbbde2576",
"type": "change",
"z": "d0f9a690e04bf3cd",
"name": "",
"rules": [
{
"t": "set",
"p": "payload",
"pt": "msg",
"to": "readPump.CIM500/ADR_204.Dosing",
"tot": "flow"
}
],
"action": "",
"property": "",
"from": "",
"to": "",
"reg": false,
"x": 310,
"y": 930,
"wires": [
[
"53c8ef23430cd71a"
]
]
},
{
"id": "73d7dd197aac9352",
"type": "rbe",
"z": "d0f9a690e04bf3cd",
"name": "",
"func": "rbe",
"gap": "",
"start": "",
"inout": "out",
"septopics": true,
"property": "payload",
"topi": "topic",
"x": 655,
"y": 900,
"wires": [
[
"e56de83b334c130d"
]
]
},
{
"id": "5fab407077ae83a8",
"type": "change",
"z": "d0f9a690e04bf3cd",
"name": "change button black",
"rules": [
{
"t": "set",
"p": "background",
"pt": "msg",
"to": "black",
"tot": "str"
}
],
"action": "",
"property": "",
"from": "",
"to": "",
"reg": false,
"x": 1025,
"y": 645,
"wires": [
[
"93cdd11b59f438af"
]
]
},
{
"id": "9c293200e2d4fb91",
"type": "change",
"z": "d0f9a690e04bf3cd",
"name": "set enabled state",
"rules": [
{
"t": "set",
"p": "enabled",
"pt": "msg",
"to": "input_remote",
"tot": "flow"
}
],
"action": "",
"property": "",
"from": "",
"to": "",
"reg": false,
"x": 1245,
"y": 720,
"wires": [
[
"4b9452657fcc1d6a"
]
]
},
{
"id": "e56de83b334c130d",
"type": "change",
"z": "d0f9a690e04bf3cd",
"name": "",
"rules": [
{
"t": "set",
"p": "input_dosing",
"pt": "flow",
"to": "payload",
"tot": "msg"
},
{
"t": "set",
"p": "background",
"pt": "msg",
"to": "rgb(255, 51, 51)",
"tot": "str"
}
],
"action": "",
"property": "",
"from": "",
"to": "",
"reg": false,
"x": 815,
"y": 900,
"wires": [
[
"aeac7511c51d451e"
]
]
},
{
"id": "42a8ebb92f2c7159",
"type": "change",
"z": "d0f9a690e04bf3cd",
"name": "change button black",
"rules": [
{
"t": "set",
"p": "background",
"pt": "msg",
"to": "black",
"tot": "str"
}
],
"action": "",
"property": "",
"from": "",
"to": "",
"reg": false,
"x": 1045,
"y": 825,
"wires": [
[
"aeac7511c51d451e"
]
]
},
{
"id": "85aaec73340d36b7",
"type": "debug",
"z": "d0f9a690e04bf3cd",
"name": "input_dosing",
"active": true,
"tosidebar": true,
"console": false,
"tostatus": false,
"complete": "payload",
"targetType": "msg",
"statusVal": "",
"statusType": "auto",
"x": 1520,
"y": 900,
"wires": []
},
{
"id": "4368da8fe6ddbe0c",
"type": "ui_group",
"name": "CONTROLPANEL",
"tab": "4ad3c40739cbf998",
"order": 2,
"disp": true,
"width": 8,
"collapse": false,
"className": ""
},
{
"id": "4ad3c40739cbf998",
"type": "ui_tab",
"name": "PUMP A",
"icon": "fa-tasks",
"order": 2,
"disabled": false,
"hidden": false
}
]
