Strange, none of the things you said work should've worked, and none of the things you said didn't work should have worked.
Let's clarify a few things:
You have LE2125 Global.
You tried to MSM with the tool lemonadep_22_O.05_210324.
You ran into errors (what errors?).
You then tried lemonadep_22_I.07_210412 and it worked.
You are running 126.96.36.199 DA
You tried to switch to Global via Oxygen Updater (did you select full or incremental?)
The switch/local upgrade succeeded, but it still says 188.8.131.52 DA
Also, have you tried to local upgrade with https://www.oneplus.com/global/support/softwareupgrade/details?code=PM1617074857015