looks like we have the same problem. 5.88.190601 is the last bootable version for my board.
If you want newer versions you have to hold the dtb: apt-mark hold linux-dtb-dev-sunxi64 and upgrade from there.
My guess is its the new lowered voltage table: https://github.com/armbian/build/blob/master/patch/kernel/sunxi-dev/0012-general-h6-new-opp-table.patch
Since then some experience stability issues and others like myself are not even able to fully boot up without random kernel panics.