This was changed some time ago. You just now got the privilege of experiencing it. 
It has to do with how they handle the viewing of events still in the process of recording.
The old way, with the live slider of the event, was AWS KVS. They abandoned that for the TUTK standard live view.
Now, with this new process, you will have to wait until the video is done recording to the cloud until you can view it.
This has been discussed in great detail here:
It has also been lobbied by many users to be returned to service over the last 3 months (every Fix-it Friday) with no action or statement from Wyze (the deafening silence is telling).
If you want it back, follow this link to the Fix-it Friday post that requests the return of the feature and like that post then add your own.