It's like I said, if you click normally (slowly) the battle starts normally, but if you click too fast then it freezes. Apparently this happens because at the same time the fight starts, you press the "search" button, it's confusing I know, but I think I can record it to show you
Already checked it. It is still hard to understand the problem, but I have an idea of several things that might be going bad. I think one might be the explore button not being protected, other might be indeed performance, and it also depends on the Android device, for example, in my test device it is not possible to repeat this error using a finger, I might need an auto clicker that can click faster than me XD.
The most likely is performance, I might have made changes on v0.81 that deteriorated performance. I think so because the time from the end of the introduction title to arriving at the beach takes almost 5 second in your case and in my test device takes only 1 second, running the same version, so on slower devices the performance degradation is probably crucial for the bug to happen.