There’s really no such thing as “congestion” in Bitcoin. Rather, Bitcoin has a limit on how many transactions it can process, which is 1 block (1 MvB/4 MWU, around 2000-4000 transactions) per 10 minutes. Miners typically select transactions paying the highest feerate to include in the next block, which means a transaction gets included only when it’s in the top-paying 1 MvB of unconfirmed transactions. When there are many high-feerate transactions waiting to be confirmed, a transaction paying a low feerate can wait potentially weeks or months (theoretically forever) to get confirmed.
If a service pauses payouts because of “congestion”, it simply means they don’t want to pay the high fees to get their transactions confirmed and prefer to wait for fees to go down.
You can check mempool.space for current fees. The minimum feerate to get into a block has been above 50 sat/vB for a few weeks, which is quite unusual.
