Unable to upload or remove apps from Bangle JS 2. Invalid JSON

Just ran into this while uploading the messages app, looking at the JS console it seems to be caused by the status update.
IIRC those are sent with a small delay after you connect. That would match what I did:

1 disconnect watch from phone
2 press upload in app loader on PC
3 select the watch and connect -> error

<COMMS> ERROR Parsing JSON SyntaxError: Unexpected token { in JSON at position 298
comms.js:261 <COMMS> Actual response:  "{\"id\":\"messages\",\"name\":\"Messages\",\"src\":\"messages.app.js\",\"icon\":\"messages.img\",\"sortorder\":-9,\"version\":\"0.47\",\"tags\":\"tool,system\",\"files\":\"messages.info,messages.app.js,messages.settings.js,messages.img,messages.wid.js,messages\",\"data\":\"messages.json,messages.settings.json;messages.jsonl\"}\r\n\r\n{\"t\":\"status\",\"bat\":100,\"chg\":0}\r\n"
ui.js:86 <TOAST>[error] Messages update failed, Error: Invalid JSON