Are you still having this problem? I don't see it myself and it might have been a cdn cache delay?

As mentiond in other places on a quick look it looks like the call to: shouldDisplayPreUpdateCheck

Has to be added in here:

Are you still having this problem? I don't see it myself and it might have been a cdn cache delay?

I'm not sure what kind of CDN cache delay could have an impact on whether the pre upgrade check is shown? It could be that the pre upgrade checker shows here because there is the error AcyMailing? Maybe @bembelimen can give some more insight here as he rewrote this stuff for 4.0

@zero-24 and others suggested that the code to stop it had been removed in 4 at some point. So The call to shouldDisplayPreUpdateCheck is not called from com_joomlaupdate https://github.com/joomla/joomla-cms/search?q=shouldDisplayPreUpdateCheck

@zero-24 and others suggested that the code to stop it had been removed in 4 at some point. So The call to shouldDisplayPreUpdateCheck is not called from com_joomlaupdate https://github.com/joomla/joomla-cms/search?q=shouldDisplayPreUpdateCheck

i still cannot replicate this

I can. STILL.
Updated Joomla 3.10.2 to Jooma 4.0.3. Now 4.0.4 is availible. And pre-update checker still shows. And as it "STUPID" (shows warning any time as ANY extension has not last version), it's hilarrious for Joomla 4
@brianteeman , do you have test Joomla 4.0.3 updated from Joomla 3.10.2, for example (with installed any NOT last version [third-party] extension)? (even, for example, pkg_search with not last version - 4.0.0-dev, as 4.0.1-dev is last version)

cache

btw, Joomla 3 have "clear" buton in extension install tab, that clear INSTALLER cache (also affects Joomla check update cache), but sadly there is no such button in Joomla 4

In J4 that cache clean should be made every time when using the button to search for updates so it doesn't need the extra button anymore.

PR #35978 should fix this issue. Please test, thanks !