If the transaction over the Avalanche Bridge seems stuck, and does not have any confirmations, it can be sped by following the steps described here.
If the Ethereum transaction has already received 35 confirmations, but, the Avalanche transaction timer seems to be stuck, check your MetaMask wallet balance on the Avalanche Network. The transaction may have already processed but is not showing up on the user interface.
Note: This also may occur if the option to "speed up" a transaction has been initiated.
Although unlikely, it is possible that the Ethereum transaction issued by the Avalanche Bridge when transferring funds to Ethereum may take an extended duration to receive 35 confirmations. This can occur if there is a sudden spike in Ethereum gas prices due to high traffic. If the transaction is not included within 200 blocks of when it was issued on Ethereum, a new transaction with a higher gas price may be issued to "unstick" the transfer.