Collapsed bootstrap select has double line again (as in prev version) and on first click to open, it closes by it self

[tamasszilagyi]

In a previous version bootstrap-select had to be changed to inline-flex so it has only one line when it is closed. I have updated it to the latest version (2.2.0) and I have the same issue again, however this time the inline-flex does no fix the issue.

Also if I click on the select dropdown the first time, it will close immediately after it opened up, than after I have to click it again to be able to use.

Also the dropdown has quite a few items and I am trying to give it a max-height as the first item will be hidden underneath the navigation menu.

I am using a PC, but the issue can be replicated on a mobile device too.

My website is https://telecetli.com

If you scroll down, you will see the filters on the left with the select dropdowns