Pico changing USB port

[JChristensen]

I am using various Raspberry Pi Pico boards with Arduino 1.8.19 running on Linux. I notice they will sometimes change ports seemingly at random, e.g. from /dev/ttyACM0 to /dev/ttyACM1. This happens often enough to be annoying and counterproductive. If I make a code change and try to upload again, it might fail because the board is now on another port; then retry the upload and it goes. Or I reset the board and I am expecting to see output in the serial monitor window, but there is nothing because the board has changed to another port.

Feels like maybe a timing issue with the PC. I am wondering if others experience this, and if there may be any recommendations to prevent it.

[Andy2No]

Maybe not related, but using arduino-pico with Arduino 1.8.19 in Windows 7, I've been having to unplug the USB lead and plug it back in again after each upload to an RP2040, for some months now.

I don't know if it started with a particular arduino-pico version or for some other reason. I don't seem to have seen much about problems like that in Win10+ though, so I've been assuming it was just a Windows 7 related problem.

The COM port for the RP2040 disappears from the IDE after the upload. It's still listed in Device Manager but TeraTerm can't see it either, until I unplug and re-plug the USB cable.

[JChristensen]

I tried Arduino IDE 2.3.4 and had much better success, until the next day when nearly every upload failed. After a bit, it seemed more reliable again. Also, an older PC seemed to work better than a newer, faster one. Just general flakiness, so hard to draw any conclusions. On the older PC, I have not observed a port change, but was getting consistent "Upload error exit status 1" for a while. My gut says it is likely not the core, more in the IDE. I was just wondering if anyone else was seeing similar behavior. Maybe this discussion is off-topic here.