That appears to be any issue with the conversion process and not Flexdash.
Strange, I don't use the moment node but inputting 1674246293.7726238 into a change node (using the node-RED inbuilt moment library), I get;
Which I assume is correct (except timezone difference)
Try;
[{"id":"54c46ebe.3b623","type":"change","z":"1543d308b342690a","name":"Change node","rules":[{"t":"set","p":"payload","pt":"msg","to":"$moment()","tot":"jsonata"}],"action":"","property":"","from":"","to":"","reg":false,"x":710,"y":1895,"wires":[["2c896b1f.98a694"]]},{"id":"2c896b1f.98a694","type":"debug","z":"1543d308b342690a","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","statusVal":"","statusType":"auto","x":880,"y":1895,"wires":[]},{"id":"7991fc04.3ff914","type":"inject","z":"1543d308b342690a","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"1674246293.7726238","payloadType":"num","x":510,"y":1895,"wires":[["54c46ebe.3b623"]]}]
For more examples about using the in-built moment library (including selecting the timezone), see this post that I wrote some time ago.
