I have my main pc where I backup my files to my Raspberry pi, I only send from pc and receive from on Pi
All was synced but I added some files recently on my PC.
And Syncthing doesn’t pick up these files, if I say rescan all it just says up to date but I am sure it is not.
The files being undetected is likely yet another issue, but please also be aware that there is a known issue of file watching not working on drive root paths in Windows (like D: in your case). This means that new files will only be detected by Syncthing during a rescan (which in your case happens every hour).