Unable to play 2K video on iPad Air 2

I have an iPhone 7 Plus, an iPhone SE (2nd gen), an iPad (5th generation) and an iPad Air2, and the iPad Air2 is the only device incapable of playing or viewing recorded 2k video events from my Eufy 2C Pro 2K camera security system.
On the iPad Air 2 I am able to play ‘Live’ 2K video on both cameras however when I endeavour to play recorded events I receive the following message: “This 2K Video Unavailable On This Device”
I have been able to download a recorded 2K video event on my iPad 5th Generation and email it as an attachment to my partner’s email address and they were able to successfully open and play the attachment on their iPad Air2 but we’re still UNABLE to play recorded 2K video events via the Eufy Security app on their iPad Air2.
Can you please advise whether there are problems relating to iPad Air 2 and viewing recorded 2K video events or any available fix?

Experienced same problem. Guided to set at lowest resolution & streaming, and then reinstall app. Seemed to work then on new videos.