Bootstrap modal conflicts with Jivo chat. How to fix?

Question

Bootstrap

Good afternoon! Please help me to solve this problem:

Website on Bootstrap 4. There is also a chat from Jivo on the website.
If the user has a modal window open, then it is impossible to write a message in the chat at the same time.

Those. the user can receive a message from the administrator, but with the modal window active, he cannot type the answer (you can only send a smiley). There is probably a layer conflict, but the Bootstrap modal has z-index: 1050, and Jivo support said that they generally have a maximum z-index: 2147483646.

Answer 1

Those. Jivo support suggested that if the tabindex attribute is not specified for the modal window, then everything works. I tried - it helped. But then the question arises: what does the order of switching focus with the Tab button on the keyboard and the inability to select the textarea field in the chat have to do with it?