My best friend studies game design, so I know problems like this too well and that always drives him crazy. You just can't find the bug yourself!
This happened to me for example: I had the problem about the jar you described with Opera, with Firefox the control had a problem (it was very difficult for you to see what you could interact with) and with Edge it ran smoothly. So maybe it's a platform specific problem?(I hope this helps at least a bit)
It is not without reason that you work together with a team on larger projects and even there bugs arise. Considering this is your first game, that was a brilliant result. So, in my opinion, this is not your fault! :)
Greetings from Germany.
P.S. I think your English is better than mine. XD