This , short summary he is still thinking about his attacks that's why they are weak. He needs to completely let go.

anyone else think jiren also has UA?

cause i think he does

what is ua

Who doesn't think he has it?

i dont think he has ultra instinct, just like kefla did not

i think its just raw power and speed

i think he does have UI the way they were talking about it (toppo and dypso)
seems like they know about UI and the way jiren fought goky and Hit seems like its the case
nothing 100% sure but i think he does know/use UI

perhaps

we saw his red aura around him only once when goku did his final hit

and after this he immediately went afk meditating, perhaps it was his "heat" coming out since he powered up to stop gokus last ditch attack and had to recharge immediately

thats what i was thinking also about why he went meditating
this arc is pretty interesting so far but id really like a twisted ending to this arc

Gokus glare gave off an effect... just like jirens
his hit with just the force of moving his hands?
dodging without even having to see the attack coming?

jiren does the same shit. He has UI thats the only thing that would give a mortal the power to be stronger than a god.
Jiren is waking up because he's scared of goku mastering it.

gods of destruction are just powerful mortals who were picked for their strength