TAP bridge not working with Windows 10 client

OvpnRider

I can't get OpenVPN TAP bridge to work with Windows 10 clients, Windows 7 works just fine.

Please note that I do need TAP bridge because I have to connect to some device that cannot be configured with a gateway, so when I (rarely) need to connect to these devices, I (would like to..) connect with TAP/bridge, for the same site, in all other cases I regularly use a TUN connection that works just fine.

I've tested 3 different Windows 10 PCs, none of them work.
I've tested 2 different Windows 7 systems and both work just fine.
All using same client software (latest openvpn-install-2.4.7-I603.exe) and very same config.ovpn file.
I tried to download and install the latest Windows TAP driver 9.23.1 from:
https://build.openvpn.net/downloads/snapshots/tap-windows-9.23.1-I601.exe
Same result, windows 10 does not work.

Two of the 3 Windows 10 PCs are very basic configuration with no other vpn client, virtualization or other fancy stuff or network adapters. Just plain Windows 10.

With Windows 10 the VPN connects nicely and I get the IP from the remote DHCP and everything looks good.

What I find very strange is that some ping respond! But it's not consistent, I may get a couple of reply and then no reply (mainly "Destination host unreachable", some "Request timed out").

Has anybody successfully used a TAP/bridge connection using Windows 10 as a client?
Any idea on what I can to to troubleshoot the problem?

Thank you in advance for any hint.

OvpnRider

I found the problem, I don't fully understand it, but it's now fixed.

The problem was that I configured the bridge (server side) to use the remote (again, server side) DHCP.
The DHCP supplied the default gateway and, for Windows 10 the metric was "low" (lower than the client side default gw), for Windows 7 was "high" (higher than the client side default gw), I'm not sure this is relevant, but that was it.

Manually removing the "remote" (VPN server side) gateway form the windows 10 client (after the VPN was up) fixed the problem.

Of course that was not a "user friendly" solution, so I changed the VPN server side config not to use (the existing) dhcp but instead I supplied an IP range for the bridge (and no gateway). Note that I don't need, nor I want, to use the bridge to route all the client traffic but use it only to access the remote subnet.

This way it works for Windows 10 clients, and of course still works with Windows 7.

It seems that there is some subtle difference (compared with Win7) in how Win10 setup route metrics when a tunnel is established.