[qubes-users] DNS problem with fedora 33 and local addresses (vpn)

Hello,

I upgraded my fedora templates to fedora 33 recently, but I have sometimes a problem with the DNS when I use a vpn (it's a vpn just for local addresses under univ-rouen.fr). I first disabled systemd-resolved and enabled NetworkManager in the TemplateVM, and when I start the vpn everything works fine.

My vpn stops automatically every 2 hours. In that cases, addresses under univ-rouen.fr are resolved by their public address (if they have one). But if I start again the vpn, local addresses are still resolved by their public address in all VM's but sys-net, at least when I use nslookup, firefox or thunderbird:

in sys-net:
$ nslookup www.univ-rouen.fr
Server: 10.0.130.11
Address: 10.0.130.11#53

www.univ-rouen.fr canonical name = woel.univ-rouen.fr.
Name: woel.univ-rouen.fr
Address: 10.0.128.52

in sys-firewall (or other VM connected to syst-firewall):
$ nslookup www.univ-rouen.fr
Server: 10.139.1.1
Address: 10.139.1.1#53

Non-authoritative answer:
www.univ-rouen.fr canonical name = woel.univ-rouen.fr.
Name: woel.univ-rouen.fr
Address: 193.52.152.49

do you have any idea how I could fix that ?

To get everything working again, I need to restart sys-net and the vpn, and sometimes just open the qubes settings for the VMs and validate (without changing any parameters) to get the dns working again (without this edit I get
$ nslookup imap.univ-rouen.fr
;; connection timed out; no servers could be reached

Thanks