Transactions logs not clearing after user migration to DAG databases from non DAG database

We have recently started moving users from non replicated databases to DAG databases.
The migration was done using the EAC. And thus it generated large amount of transaction logs.
Microsoft KB 2800556 indicates this issue.

And since then the Veeam application aware backups have been failing to clear the transaction logs.
Also the snapshot creation during Veeam backups takes a long time (close to half hour).
And during the snapshot deletion it said that backup was successfull but it could not clear transaction logs
Has anyone seen this problem? Could it be related to VSS timeout as Veeam uses Microsoft VSS writers?

Is it OK to enable circular logging temporarily to clear these logs?
I will be doing this outside the backup window as the following article suggests that if circular logging is enabled during the backup operation or the recovery operation, you cannot restore individual databases:-
https://msdn.microsoft.com/en-us/library/office/dd877017(v=exchg.150).aspx#bk_circularlogging 

And will Veeam backups be able to clear the logs there after?