Issue: Chain drops (to the inside) when shifting from small chainring to large chainring at worse. At best, shifting from small to large is not smooth.

Equipment:
Bike - 2023 Giant Defy Advanced 1 w/ !05 di2
Chainring - Ultegra 8100 12sp 50/34 (upgraded from 105 50/34)
Crank Arms - Magene P505 Base Spider Power Meter
Chain - KMC (stock on bike)
RD and cassette - 105 di2 12 speed.

Background:
Everything was fine BEFORE I switched things over to the Ultegra chainrings and new PM. When I installed the PM, I installed it with the Ultegra chainrings (will be upgrading to Ultegra in bits and pieces in the long run). As a result, I had to adjust both the low and high limits (low via app, high via screw). I have gone on 3 rides and it has gotten better each time I turn the high limit out (towards crank arm). However, this latest ride, I am beginning to wonder if it's actually the limit of the FD or something else.

There is no problem from large to small but when going from small to large, the chain sometimes does not catch the big ring. When it is successful, it is often after struggling until the chain catches. Every once in a while, there is a smooth shift. I first assumed that I had to have the perfect load on the arm for it to shift property but that doesn't really make sense, does it? I do notice that the shift is not good when gentling spinning with very little load. When the chain does mess up, it drop immediately off on the INSIDE (not outside). This tells me that is may still be the high limit. But now I'm wondering if the KMC chain doesn't work as well w/ the Ultegra chainrings? Another potential problem is the chain is worn (unlikely since I'm just a bit over 600 miles on the chain). I have a chain checker and it doesn't seem worn.

Summary of Potential Diagnosis:
1. The high limit is set too low. I believe I have about 2 more 1/2 turns to the right (out) until it will affect the crank arm.
2. KMC chain doesn't work well w/ Ultegra and switch to genuine 105 or Ultegra chain.
3. Chain is worn and do same as #2.

Any help from the more experiences cyclists? Thanks!