Im also having this problem in pc, whenever i try to enter a game in any mode, when in loading screen it freezes for about a minute and then a sign saying ''Pairing timed out. The rival has not connected. Try again'' (translated with an app) Sorry if this is misspelled, english isn't my main language.
We've confirmed that there are a small number of system/device language settings that make it impossible to matchmake successfully. The most common of these we're seeing is Czech. We're working on a fix for 2.10.
In the meantime, a workaround is to change your device language to something else. English is fine. So are most other languages. Note that the language LoR is running in does not matter - it's the underlying device language.
If that doesn't unblock you, please post your logs and I'll take a look!