A problem with uploading firmware to the pixhawk

I updated Mission Planner up to 1.3.44 version but it seems there is a problem with uploading firmware to my pixhawk. I tryed quadcopter to flash 3.4.5. It downloads the firmware shows that it uploads it then it asks to replug a usb cable and starts flashing but the bar doesn't reach the end it stops and shows an timeout error. I downgrade Mission Planner to 1.3.33 (I chosed 1.3.33 to be sure so I did flashing before without any problems) and it works.

Start by reproducing the upload flow with Mission Planner 1.3.44, a Pixhawk, and quadcopter firmware 3.4.5, then compare it with version 1.3.33. Observe the replug step and timeout, and identify the firmware-upload entry point involved; done means the newer version completes flashing without the timeout.

Written by the indexing model from the issue text.