Line 90 - 1 OS detected
Line 92 - OS#1: Windows 10 or 11 on sdb2

No sign of Ubuntu in the report (as you mentioned in post no. 1 "gave an error "Installer terminated abnormally" - reasons were not specified".)

Line 13 - Windows 7/8/10/11/2012 is installed in the MBR of /dev/sdb

Your Windows OS is installed in old style BIOS/MBR yet your PC is EFI compatible as detailed here
Line 103 - The firmware is EFI-compatible, and is set in EFI-mode for this live-session.

In order to have have a robust dual boot for the future, my suggestion is:-
Back up all your personal data
Re-install Windows 10/11 on one disk in UEFI mode with GPT.
Restore Windows data and check if everything is OK

Disconnect, de-activate, isolate via UEFI settings or physically remove existing Windows OS drive so that only the second target drive is accessible
Boot Ubuntu live and check that you are in UEFI mode
Open a terminal and enter:-
[ -d /sys/firmware/efi ] && echo "UEFI" || echo "Legacy"
Create GPT on your target disk using gparted
Open gparted > Device > Create Partition Table > Select gpt
Allow the installer to automatically create the necessary partitions (or your preferred configuration)
Double check that an EFI partition will be created

Boot each system independently via UEFI boot screen
Boot priority can be controlled by UEFI

You can later create a partition (ntfs format) to share between each OS if desired.