Serial monitor is not cleared after upload on STM32 Arduino core

[PerennialNovice]

Describe your environment

latest sloeber 4.4.3 product
OS: Win 11
STM32 Arduino Core 2.7.1: https://github.com/stm32duino/BoardManagerFiles/raw/main/package_stmicroelectronics_index.json

Describe the bug

After upload, the serial monitor is not cleared, even when the checkbox is ticket in Sloeber -> Preferences

I have seen this on a custom board with SWD upload and on a Nucleo32 with mass storage upload

To Reproduce

1. install STM32 Arduino Core
2. create new project with serial output
3. compile, download
4. activate serial port
5. see output
6. check Clean Serial monitor after upload and Switch to Serial monitor after upload in the menu Sloeber -> Preferences
7. upload project again
8. previous contents is still in serial monitor

[jantje]

I'll have a look after I finished #1126 (don't hold your breath)

[PerennialNovice]

on a fresh install of sloeber & workspace, this seems to not happen anymore...

[jantje]

I could reproduce it so something is off.

[PerennialNovice]

I now can confirm that the serial monitor is randomly* cleared or not after upload on windows and on linux installations...

* at least I was not able to find out a rule as to when it is cleared or not. Sometimes it is cleared 5 times in a row, sometimes not at all during maaany uploads. Only thing: it seems to be cleared far less often then not.

[jantje]

Last times I checked it worked fine.
It looks like this one will be hard to fix.