As described in the "Battlefield 6 Maps, Modes & Portal" trailer (at 3:20) Verified Portal Experiences are supposed to have "full progression and XP gain".
This was true until earlier today, it is currently not true anymore. Only "Match Completion Bonus" seems to be active on Verified Portal Experiences. The "Win Bonus", "Score", "Accolades" is disabled. The four secondary progressions "Mastery XP", "Daily Missions", "Assignments" and "Other Challenges" are also disabled.
I assume this is a bug on your part.
It hasn't been officially stated by EA but they did infact gut the xp gain in Portal due to the amount of Bot farms there are/were in the server space. Unfortunately from what I've heard it also affects legit games that have bots in it so it sucks there but there is a reason behind it and not just a bug.
