SP 2016 patching with SQL 2016 Always on

On the SQL Server side it won't break anything. The basic steps are:

1. Patch your Secondary/Replica first.
2. Do fail-over and make your secondary as Primary.
3. Patch the previous primary (currently secondary)
4. Do fail-back and make your current secondary as Primary again.

SQL SERVER – How to Apply Patch in AlwaysOn Availability Group Configuration?
https://blog.sqlauthority.com/2017/03/04/sql-server-apply-patch-alwayson-availability-group-configuration/

I am talking about SharePoint patching, not SQL.

We have only 1 SP farm.

Did you mean patch secondary mean, the 2nd node of SQL?

When attempting for high availability, this is in general what you'd do -- note that order of patching doesn't matter, but we'll be keeping the service highly available.

For your app and search servers, patch one node member type at a time. This way one of the node member types is always online. For your FEs, do the same but you'll want to remove the downed note from the load balancer, and bring it back online when the patching is completed. After you have all nodes patched, you need to run the config wizard. Likewise, patch only one of each type at a time and for the FEs, remove it from the load balancer.

https://video2.skills-academy.com/en-us/sharepoint/upgrade-and-update/sharepoint-server-2016-zero-downtime-patching-steps

Thanks, Trevor

I was thinking more from AG point of view.
Can it break the PS config if the dbs are in sync status.
I have faced this issue in SP2013 with mirroring.