Nikāya vs Saṃvāsa

Hello,

Does anyone here happen to know whether or not the different Nikāyas in Sri Lanka and Myanmar function practically as different Saṃvāsa/affiliations?

In other words, do they hold it contrary to Vinaya for different Nikāyas to sit together for a pāṭimokkha recitation?

Thanks in advance

I don’t believe this to be the case in Sri Lanka.