Since updating the code I have not seen any 500 error page on my own forum or on MLF. I gather I don't need to update to 2.4.19.1 if it is just for the things I updated manually?

Since getting the site working right on 2.4.19 I have noticed maybe 2 or 3 times:

As a guest
opening a full thread
clicking the login link
logging in with credentials
the previous open thread that you were on normally loads again (this is how it should work)

but 2 or 3 times now I notice

As a guest
opening a full thread
clicking the login link
logging in with credentials
a completely random open thread loads (one that I have not even been to in that session)

Like I say it has only happened a few times and I cannot pinpoint a sequence of why. Now that I have reported it maybe you can tell why? I don't know.

Thanks