BigSur SMB connection over site to site vpn doesn't work on silicon m1 MBA

Hi,

we have site to site VPN connect to our fileserver. With BigSur on a M1 MBA I can connect to the shares, but it is very slow and we have no correct authentification. Some folders are locked, then not, then again locked ..., that's crazy.

Many kernel (smbfs) errors like this : smb_iod_reconnect: id 0 Reconnect Tree Connect failed to share SOFTWARE on server .... error=57

I'm now on 11.3, the problem is still there.

In the same network I had no problem to connect to the shares.

We have more Macs with BigSur too behind the site to site vpn, but only the MBA M1 has such problems .

Please help, its very urgent

Regards

René