all full-size Colt series 70 and later 1911 9mm pistols are conversions of the .38 Super Auto variation of the 1911. as such, you might need something like the EGW magazine catch, which allows the magazine to sit slightly higher in the frame (
https://www.egwguns.com/hd-higher-mag-catch-machined-from-barstock-checkered-blue), however this is not true of specific stocking dealer models or for their competition or custom shop pistols.
what weight spring is being used? a 9mm recoil spring should be between 10# and 14#, with 14# being the factory spring. the spring should have 23 coils. for 9mm 1911 pistols i've built for customers, i generally use a 12# chrome silicate spring.
what is the ejection pattern when it works properly? it should eject between 3:30 and 4 o'clock. some colt .38 Super Auto conversions sold as factory 9mm pistols will have the shorter .38 Super Auto ejector:
View attachment 2000883
instead of the correct ejector:
View attachment 2000927
the ejector helps guide the cartridge from the magazine feed lips to the ramp and upwards into the chamber. a too-short ejector will not guide long enough to ensure reliable feeding. also, check the magazine for a burr on the interior rear, which can slow or impede the movement of the follower. these magazine bodies are often welded from an extrusion or formed around a mandrel and manufacturing issues can creep up now and then. the ramp should also have a very smooth feel - nothing noticeable with the finger nail or to the eye as a defect.