On Android devices? If so: how? :)
I use Tailscale, purely out of laziness and a willingness to trust them today, but I'd move to head scale if either of those caveats changed.
OpenVPN does seem to always work everywhere (presumably because outside contractors and support personnel use OpenVPN when onsite so it's a squeaky wheel that matters) so I've moved to that instead. Beyond that I can't figure out what the hell is the problem and the way IT works, they have no reason to fix it. I did get them to somewhat work on it by reporting Google VPN as randomly failing, but they just fixed Google VPN and nothing more than that. So anyway wireguard is great until you encounter bullshit corporate firewalls.