Flashing Tinker (or other firmware) works well both OTA and via USB. With other firmware, it all works as normal.
I’ve logged it as a bug https://github.com/particle-iot/firmware/issues/1550
If I first engage Safe Mode and then perform the clearing procedure, the clearing works! It appears that I can also set the wifi credentials this way, so that’s actually great?!? Now we have a workaround while the bug can be solved!
I’m sitting here diff’ing various commits. I know that the problem was introduced after April 5th. It’s a lot of commits there, so I’ll check out each of them, compile and test. When I know exactly when it was introduced, I’ll analyse the diff to try to understand what is causing this.