Hi Miron,
I remember a similar thread about using Reach RS2 as a base station in POSPac. Once we added a line with leap seconds to navigation files and made the epochs’ seconds integer, everything started to work like a charm.
So I agree with Igor’s suggestion. I’d record a 1-hour log in an open sky area and try to upload it to POSPac.
Averaging the data in the Base settings is needed to configure the base for RTK. For PPK, it’s not needed, so you can go straight to Logging.