Interesting find! Trying to read the "test context works" state in a function node fails:
[{"id":"f20fd17d.b0cdd","type":"inject","z":"630bc809.3cefa8","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"","payloadType":"date","x":140,"y":1480,"wires":[["71aa708a.cb207"]]},{"id":"71aa708a.cb207","type":"change","z":"630bc809.3cefa8","name":"","rules":[{"t":"set","p":"\"test context works\"","pt":"flow","to":"payload","tot":"msg"}],"action":"","property":"","from":"","to":"","reg":false,"x":355,"y":1480,"wires":[[]]},{"id":"655bebce.96bbf4","type":"inject","z":"630bc809.3cefa8","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"","payloadType":"str","x":145,"y":1520,"wires":[["b0ab4b49.050988"]]},{"id":"b0ab4b49.050988","type":"change","z":"630bc809.3cefa8","name":"get \"test context works\"","rules":[{"t":"set","p":"payload","pt":"msg","to":"\"test context works\"","tot":"flow"}],"action":"","property":"","from":"","to":"","reg":false,"x":345,"y":1520,"wires":[["a43a66e3.f11ef8"]]},{"id":"a43a66e3.f11ef8","type":"debug","z":"630bc809.3cefa8","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","statusVal":"","statusType":"auto","x":550,"y":1520,"wires":[]},{"id":"dcb2dc5b.3a9f5","type":"inject","z":"630bc809.3cefa8","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"","payloadType":"str","x":150,"y":1560,"wires":[["e1ed036d.063a7"]]},{"id":"68cb3090.876aa","type":"debug","z":"630bc809.3cefa8","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","statusVal":"","statusType":"auto","x":555,"y":1560,"wires":[]},{"id":"e1ed036d.063a7","type":"function","z":"630bc809.3cefa8","name":"get \"test context works\"","func":"return { payload: flow.get(\"test context works\") }","outputs":1,"noerr":0,"initialize":"","finalize":"","libs":[],"x":350,"y":1560,"wires":[["68cb3090.876aa"]]}]
And the context variable doesn't show at all in the context panel in the admin UI.
I never used change nodes for the contact, only function nodes, and there it worked fine.