So, I did try to reconstruct the situation on my dd-WRT router and both connections work simultaneously.
For the OpenVPN client I did some Policy Based Routing so only a certain IP range (x.x.x.100 to x.x.x.150) shall get routed over the OpenVPN connection and the rest is normally connected to the WAN.
For Wireguard I didn’t change anything and I can establish a WG connection via LTE to my home network at the same time.
so your statement “Your data goes one way or another.” may be true on the GL router but in reality it’s no big deal to get this working
actual settings on the GL-MV1000W
VPN Policy settings:
Use VPN for all processes on the router --> deactivated
Rule: Only allow the following use VPN: 192.168.0.101
if I activate the the Wireguard Server the following error prompts: WARNING: Conflicts! All other VPN services must be stopped first.
So I have proven that this setup works on a dd-wrt router, so technically this setup works, is there something I can change in the openWRT setup?
BTW DDNS Service is also runnig on den dd-wrt if openVPN and Wireguard is running…