X-T3 locking up on latest firmware 3.10

[BruceClement]

I never had this issue until I applied the 3.01 firmware update and all of a sudden my camera is randomly locking up.  Then I updated it to the currently latest version, 3.10 and it is still doing it.  It has done it with my xf16-55 mounted, xf80 mounted and xf50-140 mounted.  I've had Godox speedlights on it as well as a remote trigger and it has happened and it has happened without any speedlight or trigger attached.  Batteries are Fuji batteries NPW-126S.

When it locks up the camera goes completely non-responsive.  Nothing shows in the EVF or on the back screen and the little orange indicator light in the thumb brace comes on and stays on.  Turning it on and off does nothing.  I have to pop the battery out.  I've found no rhyme or reason as to when it happens.  It just does.  Sometimes multiple times in a row and then it will be fine for a while.

Anyone have any insight?  I wish I could go back to the firmware prior to 3.01 as it worked perfectly for me.

[BobJ]

The firmware update may be coincidence. I had this experience with an x-t2. it was caused by a faulty SD card. Swopping them around will not work. The bad one will cause this fault in either slot. Replace both in the first instance and see what happens. I do hope that it is that simple for you too.

[PoetDoc]

I agree with BobJ. Just had a problem and thought it might be 3.10 firmware, but it was a faulty SD card that could still read and write, but it slowed down startup to a glacial 7 seconds. Switched out both cards for new ones (formatted in camera)and problem went away.

[BruceClement]

Thanks guys.  I reached out to Fuji service and they had me ship it for service and they are replacing the mainboard right now but I will check my cards as well.  I can't remember if I was using the same set of cards each time it locked up or not but cards are cheap to replace so I will swap them just in case.

[BruceClement]

Final update on this.  Fuji service replaced the mainboard on my X-T3 as the OTA update to 3.1 appears to have corrupted it somehow.  It took them 3 weeks to repair it and send it back but it is working great now.  Put the new firmware on using the old school method and can see an improvement in focus speed now as well.