Thank you for the file.
There’s one last thing to try with your current setup.
Some have said that the system could get slower due to the new Sync3 version you installed and old/corrupted map installation.
So, take a look at this guide: Tutorial: Sync 3.0.20204 with 2022 EU 2.21 (F11) Map Installation
I’m not sure if that’s your case exactly, since you mentioned NAV stopped working… but it’s worth a shot since your maps are really old as well.