How often does the app upload the changes? It seems to me that it doesn’t do it instantly but rather after hours or days, grouping everything you modified together in a single changeset
Edit: I tested it a bit and I realised that I had the mobile data off for CoMaps, which made the app keep everything in the cache until I connected to a WiFi. So, if connected to the internet, it creates a changeset with each edit that it then uploads within a second.