Very old app version is being showed in the Firebase Latest release dashboard

[Egidijus]

hello!

Recently I noticed that very old app version (released 4 months ago) is being showed in the “Latest release” dashboard. It looks very strange because normally when I’m releasing new app version then the oldest version adoption count decreases almost to zero after some time. But adoption count of this version is always about 10 percent or more per those 4 months.

Also other strange things for this version are:

• daily user engagements is ~60 min or more when normally for other version it is ~8min.
• sessions count is about ~500K when normally it is ~20K
• all sessions country is US only when normally app is supported in 14 countries
• every day active users for this version shows up to 10 users and all of them are from US
• when I‘m seeing over "StreamView" then this version users devices are not recognised. It is being showed as “Unknown device”.

This old app version didn’t have any major changes and also with next app version everything was fine, so I don’t think, that the problem is in app. Do you have any thoughts about what could be here or maybe do you have any experiences with that?  Because this version distract statistics of the all app versions. 

thanks for any advices.