SOLVED... & it was so easy.. ONLY ONE STEP (OK, two.. no uninstalling or reinstalling or re-downloading needed)
Thanks to you all, so I had to post it here:
System: Macbook Pro w/M1 Pro + Monterey.
Problem was: New computer came with Monterey, migrated everything from old Macbook w/M1 + Big Sur, all but Native worked.
Solution:
1. (Not sure if this step is necessary but probably it helped) Run Logic, go to Plugin Manager and if Helix Native isn't validated, quit, run again in Rosetta, go to Plugin Manager, select Native and "rescan selection" and see it get enabled.. then quit Logic.
2. In Finder top menu bar, click Go, press the Option/Alt Key to reveal "Library". Under Library > Application Support > Line 6 find "Helix Native" folder and rename or delete it (rename is better just in case) That's it. NOTE THAT YOU'LL LOSE ALL PRESETS AND IR'S AND SETTINGS.. I had them on my Helix Floor..
Now run Logic WITHOUT Rosetta, check if Native's still "enabled".. and then in a new track, insert Native and VOILA!
Just like I guessed, an existing setting or preset must have caused the problem and it was located in that folder that I renamed. Once it was renamed or deleted, Native recreates that folder this time without the problem.
I didn't have to delete Native at all, I just luckily found where the problem was and it's gone.. Finally I can use Native after 2 months.. All the posts here helped, so thank you, hope this works for others :)