I’d be interested to hear on how you get on with an apk downgrade. Don’t forget you will have to disable automatic upgrades for that app. Also don’t forget that at some point you will almost certainly be forced to move on, as the version will cease to be supported, and then you will potentially be faced with the same issues.
Consider also that if ever you need support from Blink, the first thing they will ask you to do is confirm that all devices that access your account are on the latest version, because otherwise support could be looking at, and trying to solve, issues that are already addressed in the latest version. This approach is standard practice, and should practically be their first question.
Perhaps, and this is only a suggestion, better to report the issues you face with the current app, on the device in question, which will allow the issues to be fixed for all. At this time they should also be able to advise you if it is a known issue, and if it simply needs you to make a setting change on your device, such as how you have Wi-Fi to mobile data switching set up, or similar such setting, which can impact performance.