Question about Incident Table

Working for a company that would update their instances, but would skip records.

When I started, the instances had hundreds of updates available they had never installed. 

They finally updated the instances, with some, but not all updates. 

They are having random problems with the Incident module. 

The Incident table shows in the Versions tab of the table, with an update set / version back in 2019.

Comparing it to my PDI, aside from fields they've added, there are field missing/extra that don't match up to the PDI. 

Does this mean this IS the current version of that table? Is the version tab only showing Update set version?

How do you find out what actual version this table is on? 
If I look at the PDI, go to the Incident table, then select Copy SysID, if I compare it to two different PDIs I have access to, they are the same. But they are not the same between the PDI and this company's.