I am running TeXstudio 4.2.2 on Windows 10 and observe the following error: During writing sessions, I routinely save my file by hitting CTRL + S. However, when doing so after an extended writing session, the file on the disk is not altered. Also File -> Save does not work, the file on the disk remains at an outdated version. Nevertheless, in TeXStudio, the floppy-drive symbol that reminds me to save my data, vanishes also in those cases.

At first, I did not notice this until I pressed CTRL+Z to revert some change. If the above described error happens, also the "undo history" is corrupt and the file is changed at some random location in the text.

I know, these two error descriptions are yet very vague and I cannot reproduce the error on purpose. But it happens daily and is super frustrating if you close TeXStudio and the next day you notice that at least half a day worth of work is lost. Let me know if there is anything I can do to help you find this bug.

This error also ocurred in 4.2.1. The file is stored locally in a git-repository (i.e. it is not stored on a remote server).