OS became corrupted
I have a MacBook Pro (13-inch, 2017, Two Thunderbolt 3 ports) that the OS became corrupted (on which OS Catalina was installed). When booting in recovery mode, it would try to install an older OS, which would fail because it could not install on an APFS formatted drive. I can boot from an external drive, but I cannot backup or copy the files from the internal drive. Working with audio on the internal drive, files are not able to playback files without gaps, which I suspect is related to the system corruption. I downloaded the OS Big Sur installer, it won't install on the internal drive, reporting "received XPC error Connection interrupted". As I need some files that are on that drive, I really don;'t want to erase it. I appreciate any help, thanks!