I don’t know much about MaxDB, but I see a long thread of discussion in the R&D forums with 7.9 mentioned as well: https://forums.veeam.com/veeam-backup-replication-f2/create-a-maxdb-sap-backup-t5281.html

The most relevant post by @Andreas Neufert seems to be: https://forums.veeam.com/post201326.html#p201326

You could also check out this article on my blog. I ended up successful with those scripts, based upon the Veeam forums snippets ! Those scripts allow to suspend the logwriter and take a successful backup of the VM which hosts the MaxDB database

https://www.virtualhome.blog/2020/07/29/how-to-backup-sap-maxdb-with-veeam/