AMH gone down suddenly. Took gone wrong?

Me and my wife both are of age 32. We are trying to conceive since last 2 years. 6 months ago we consulted gynecologist and he suggested us to do IUI. At that time AMH level was 3.45. We did One IUI which failed then we took break of couple of months as my wife's father got infected by covid and eventually he passed away. After that we also completed both dose of vaccine(Coaxin). All this happened in span of two months. After that we did two more IUI attempt but both failed again. As suggested by gynecologist we repeated AMH test but this time report was dangerously shocking. AMH level is just 1.02. We couldn't understand why and how this has happened. How come AMH can go low drastically? What could be the reason behind it? Is it bacause of vaccine or any fertility treatment(IUI with Humog 75 HP injections) we took gone wrong? So many questions are going in our mind right now.