These guys both speak Russian (and don't have any other common language). Both countries have substantial Russian minorities. But they now refuse to speak Russian to each other because of Putin's war on Ukraine.
This is yet another way in which Putin's war - rationalized in part because of the supposed need to protect the Russian-speaking population in Ukraine - has backfired. The predictable result has been a backlash against Russia and all things Russian in neighboring countries.
I think it is also likely that the majority populations in these states will now view their Russian minorities with greater suspicion. If that in Ukraine has been used as a pretext for Russian irredentism, why not the others?