Sometimes, you need to use : SQLserver instant name + port (1433).  I would use another port if you can.

The error message could indicate you have a network connectivity /...

Have you tried to repair the SQL installation?   Clean registry / ensure programs are un-installed correctly.

If yes, then re-install on a different folder.  This helps sometimes.

Note: As always, please check...

If your max memory is 512 GB.   I would give 1/4 to the OS and apps.  The rest goes to SQL.

If you have VMs, I would initialize the Min memory...

I would not use some of these monitoring tools.   They slow things down.

Perfmon gives you good performance graphs for KPI.  Please check out Idera.

A good database design is a must with normal forms 1,2,3, others met.

+ good indexes

+ Partitioning is best.

+ High Availability groups

-> Hardware choices

+ RAID 10 or better

+ Load balancer

+ Disk...

Please read on temptdb database contention.

https://www.sqlshack.com/sql-server-tempdb-database-and-latch-contention/

A small inconvenience!

Yes, SSRS resource should be a shared resource on another SQL server for node 1 and node 2 on AG.

Agree with ANT-GREEN notes.

Database design books - college level

SQL server hand books - lots to choose from.  Grant Fritchey has some!

Videos:

Brent Ozar videos / Pinal Dave - SQL authority / (Jonathan Kehayias /...

I understand you are trying to preserve some data at the subscription, and save time.   Perhaps, try this  steps:

• Stop the replication services.
• Backup the subscription database.
• Drop the replication...

Yes, the windows system event viewer will tell you if there is a hard drive error in addition to the SQL logs.

I hope you can afford a raid 10 one...

WMI provider errors could mean a lot of things.   One of them could be your SQL install got damaged some what.

Try this solution from Microsoft:

To fix a corrupt SQLPS module,...

Create an alert that reads from one of the system catalog views and notify an operator by email when the free space of the SQL Transaction Log file becomes under...

Simply create an alert that reads from one of the system catalog views and notify an operator by email when the free space of the SQL Transaction Log file becomes...