In my case 64GB card from Lexar was working better. But not flawless. But I found a youtube video where Lexar cards in general were told to be problematic.https://www.youtube.com/watch?v=N2uR9M4Ua7oAfter the fix they work for me. So it was the faulty...
Update for my issue - I finally took the effort and time to send it to the warranty repair - they replaced the motherboard on their cost and so far the camera works fine with all combinations of any of my cards - SD, micro SD, slow or fast, regardles...
I have had the same issue with my R6 M2 in the same way with slot 1. To the point that when I first received the camera it wouldn't recognize anything in slot 1 (while slot 2 was empty), I bought a set of new cards and it only worked when i set it in...
