[Check out O2's coverage checker](https://www.o2.co.uk/coveragechecker?cm_mmc=affiliate-_-204909-_-blank-_-blank&awc=3235_1597840599_349ac3d4b42ad17b5fcbf8f48abb766e). Glasgow has practically no 5G coverage, especially not inside. Outdoors walking around the city centre, maybe.
You'll get great 4G pretty much everywhere though.