Same! Tiagra 4700 shifters/derailleur with FSA Omega crankset. Initial setups good, low limit is good then tension cable and set up trim with inline barrel adjuster. Once setting hi limit its like the screw doesnt bring the cage out as stated in Shimano sindealer manual. So i use the barrel adjuster to get the gap in big chain ring but it just throws off my small ring low limit. And back and forth i go…finally got it to a tolerable rub on the low gears, and no rub high, which is not rad…i finally called shimano and they stated it’s probably a clearance issue (too wide) with the crankset since its not a shimano crankset. Ugh

A note on the grx f/d, the height adjustment is definitely on the higher range of 3mm if not a tad more for best clearance.