Thanks for the additional comments.
Now, to unsettle your day.
IF my GUESS
is correct then you do have a power problem or an installation problem.
SWAG says check your antennas to make certain that at least one set is always clear of battery pack shadows, engine shadows etc.
I haven't even been able to get that result while trying but it is a potential even if it is a low percentage 'call' based upon my experience.
Again, since you are experiencing problems the Flight Log can save you a lot of guess work as it will give you not only the fades, frame losses and holds if any but will also ID the antenna involved.
While QC (the firmware update) will recover your system let's not ignore the fact that the problem still exists (I.E. the cause).
Only when we find and correct that will you have 'solved' your problem.