/messages path returns 404 and crashes app for streamlit 1.19

[prhbrt]

I've tried to make a minimal failing example, yet these examples both using the streamlit versions 1.17 and 1.19 seem to work fine. Yet in my particular (complex) app the searchbox crashes the app just after typing with version 1.19 but not version 1.17, in the network console I can notice a HTTP 404 on the /messages request.

As said, unfortunately I can't reproduce in an elegant way and hence you can't fix this, but still wanted to document this for others who may run into the same issue.