Select List Lag

I run into quite an unexpected bug (I hope its not some platform limitation), making select list dropdown menu practically unusable. I know there is lot of data, but as you can see from vide loading data is not a problem because scroll works perfectly, also if you type data via keyboard filtering works mostly fine.
Its just that dropdown menu can be really slow to open (on my colleague laptop its even slower) and selecting anything from the list is almost impossible.
I never had this problem in some similar software that we were using with same or bigger amount of data. Is there any way to fix this?

Here is example of what I mean: