ok, yes I saw, but with Ive always need to re upload wireguard, vpn policy based routing, LuCi, etc
when I use snapshot, I thought wireguard was there by default now
Oh, you are talking about self-installed add-on packages, not the actual config settings...
Yes, you need to reinstall those.
There are some scripts to help you (search forum), and sysupgrade script also has parameters to store a list of installed packages.
(In the long run the easiest approach is to build your personal firmware with all needed packages included.)