One circuit, some lights dimmer than others

Hi there, new to forum so I hope I'm posting in the right place. I have two rows of MR16 awning lights that are on the same circuit, but half the lights seem not to be receiving enough power. They are on, but very dim, compared to the other row, which has full power. Noticed this when swapping bulbs out. All the fixtures have new lamps. Tried the breaker, no change/same result. Looking for any advice on what the issue could be. Loose connection somewhere? But thought if that was the case, they might be flickering. Just seems like not enough power is getting to the dim row, but why?

Thank you for your help.

One circuit, some lights dimmer than others