Synchronization of 5G TDD between two operators

,
1

Hi Experts!
Let me to describe my issue that I am thinking about.
There are 2 operators (Operator 1, Operator 2). They are share the same 5G band, for instance n78 (it is TDD frequency). All 5G optimization articles say that both operators should use the same TDD frame structure otherwise they will make interference to each other if Operator 1 use DL slot, but Operator 2 use UL slot simultaneously. Ok, it seems very logical, but obviosly that in real life both operators use different NR-ARFCNs, so my question is:
Why does different TDD frame structure cause interference between operators if they use different NR-ARFCN?
Ok, Operator 1 use DL timeslot, Operator 2 simultaneously use UL timeslot, but they are using different frequencies.