Hi, new to Bitcoin and just trying to understand the technology a bit more.

From my understanding there are a few thousand (2.5k on average) transactions per block of Bitcoin. Do the miners when they validate the transactions also communicate this to each other in real time OR the validations are done in isolation on each miner and only added to the chain once all the transactions are bundled in a block + hashed? If its the latter does it not mean some validations are not logged in the blockchain?

Sorry for my confusion.. just trying to understand.