Upboard hangs on reboot

I've installed the new Ubuntu 20.04 with your custom kernel, but noticed that the upboard hangs everytime I reboot it.
I've already tried to add those lines in the blacklist.conf (https://wiki.up-community.org/Ubuntu_20.04#Hang_on_Shutdown_or_Reboot_for_UP_Board), but it doesn't work for me.
What else could I do?
Comments
I get this message over and over again:
BUG: soft lockup - CPU#0 stuck for 22s! [systemd-shutdow:1]
Hi Tone,
I'm facing the same issue have you found a solution by any chance?
No.
I've tried that:
https://wiki.archlinux.org/index.php/UP_Board#Reboot_causing_kernel_panic
but it didn't work.
And found an older kernel bug:
https://lore.kernel.org/patchwork/patch/817189/
But the kernel from aaeon is based on 5.4. so it is already fixed.
I've no idea. If I google the log-message it's probably a kernel problem
Here the complete log:

@Laurent DOUCHY: is Ubuntu also your second partition?
It seems to be the blacklist didn't work.
Look at the "RIP" line. dw_dmac_core hangs.
But I already updated my blacklist:
/etc/modprobe.d/blacklist.conf
do i need to do anything else to make it update?
SOLUTION:
After updating the blacklist I had to rebuild the kernel (I think?) with
Why isn't this in the Wiki?
I'm running Ubuntu 20.04, also with the custom 5.4 kernel, and a reboot was not sufficient for me. Running
sudo update-initramfs -u
solved the problem. Thanks, @Tone.That is probably required from Ubuntu 20.04 onwards, we updated the wiki with that step.
Thanks for your input.