Dears: I am editing this post because after 2 weeks, Line6 support recommended me to bring back my unit to the shop and get a new one because I was probably having a hardware issue.
I did it and I must say that the new unit works like a charm. I can do anything I should be able to do without any issue so far.
I am keeping my original post below this lines for rhe sake of completeness but I was wrong on my guesses:
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Thank you "dugbug": I was about to return my Amplifi 30 amp because it randomly stopped working, got bluetooth disconnections ,etc... and thanks to your post I just realized that what happened is that it WAS CRASHING because I saved a tone in Bank 1A.
I did a factory reset and now works like a champ UNLESS I "dare" to save a tone to the unit. I am happy again, since the unit is very cool.. actually it made me play the guitar again regularly!
So: JUST DO NOT EVER USE THE TONE SAVING "FEATURE" TO THE DEVICE: it will very likely corrupt your device memory.
Final note: this is still happening on firmware 2.60 which is UNBELIEVABLE... after 2-3 years and Line6 didn't manage to fix such a stupid bug.... Here is my sugestion to Line6: if you cannot pay a single developer to fix this bug properly, why don't you just open source the code. I am sure that the community will do AMAZING things with this cool amp as well as fixing the F...ING bug.
Enjoy!