Disconnect mid game, cannot reconnect unless restart PC

Hi,

TLDR; DC midgame, can't reconnect. League can only reconnect after restarting PC. Same exact issue happens to gf, although never at the same time. No further network connectivity issues.

Lately my and my girlfriend have had this happen every few games to us (although separately: we've never had it happen at the same time, always over different games).

1. Mid game I disconnect, without apparent packet loss or connectivity issues.
2. After closing the game and returning to the client, I click 'reconnect',
3. Reconnecting only gives a black screen with loading signal (and on rare occasions a message of connectivity failure).
4. Restarting client doesn't do anything.
5. After restarting my PC, starting the client again, the issue is resolved, usually on the first try (sometimes I have to reconnect twice).
6. At that point, say 6 minutes after disconnecting, the game is obviously already lost :p

I went through the connectivity issues troubleshooter, but no joy. Also tried to find earlier posts - but couldn't quite figure it out. As we both experience it, it kind of feels like there is something fishy going on with our IP or something.. But then again, it never happens simultaneously (which then leads me to think it's not a network issue).

Some info: I am using a wired connection, gf uses WIFI. We both use win10. We never have any other network-related issues otherwise (17 ping, 0 spikes), and the network checker provided in League's troubleshoot rates our connection 97/100.

I'd appreciate any response, thank you.