Version tracking sometimes doesn't pick up the right Installed vs Latest

[AttaInsularis]

Have GOS and therefore there is GPS, Accrescent, Obtainium and nowadays Zapstore, some use the F-Droid.

It happens to me, that in Obtainium (having auto-update checking OFF and update info is checked only if the detail of the app is opened) the app isn't picking up the real installed version in Android.

The app is updated from different source. For most of the apps the check perform notice the app is on newest version and stop offering the update.

But sometimes despite app is already updated the Obtainium doesn't pick up the change and forcing me to download update.

I'm confused because not remembering the update is already done could update it again, now from Obtainium.
In general unsure if this is a bug or just some misconfiguration.

Read the FAQ 'How apps are tracked'

"If version detection is disabled for an app, you may occasionally run into inconsistencies between the real version of the app installed on your system and the version shown in the Obtainium UI." - I believe that it's not disabled, even not know where is such option in settings. So should have default setting here.

There is a mark/check icon in bottom part of the screen - to 'mark as updated'.

It's the pseudo-version .apk., from GH repo, so not the HTML source.
('Please ensure your request is an actual bug and not intended behavior (this is frequently the case for issues involving version strings and the HTML source.))'

--
Solved it by re-adding the source again.

Now it shows the app up to date, as latest.

But I'm curious what is wrong and if I can do it better next time.