I am getting this error when trying to mount my Samsung phone (Android 10, December patch) on Solus Budgie (both current and lts kernels). In the past i would connect my phone, make sure file transfer is enable, and mount it, and it would work, but now i only get this error. File transfer works with Windows like it did in the past.
Unable to reproduce the issue with my device (OnePlus 3T) and libmtp hasn't been updated since September. Others in that thread have also validated that their device works, sounds like an issue with your device specifically, and given you mention a "December patch", it's entirely possible it was the result of that. I would suggest reaching out to Samsung via their support forums.
I can confirm I've got the same problem since at least the December 18th Solus update. However, in my case, no concurrent updates happened for my device (Galaxy Tab S6 Lite running Android 10 November update). I noticed the issue following the December 18th update, but it had been a while since I tried to move files to my Samsung device. So I'm wondering if the issue was ultimately caused by the Nautilus or kernel 5.10.x update, although it seems limited to Samsung devices because I can't reproduce it on my Pixel phone running Android 10 either.
Like mentioned in the forum thread, image transfer still works though, so it's a workaround for now to transfer files.
I can also confirm I now have the same problem, my Samsung Galaxy S7 used to work well with Solus, and since a recent update (couldn't say which one) it stopped working and now displays the same error.
Edited to add that my android version did NOT get any update since 2019 so Android might not be at fault here.