Modal popup issue following upgrade to Joomla! 3.10.2 or JFBC new installation

Hello!
I  am trying to fix a bug for several days, I read all the doc and your support forum info, but I am still blocked. This strange, as jfbconnect works very ewll on J4 ! 

Using Joomla  Joomla! 3.10.2  
_jfbconnect_v9.0.152,
JFBConnect installed but social netrwork login button not activated.

For unknown reason it seems that the login view settings is stocked on always visible... while the login view settings has always been set to Modal Popup. I disabled the JQuery. The ck templates loads its own. I cleared the cache, disabled JFBconnect... same problem. 
I progressed slightly since I added the below coding on the theme page as your recommended, the modal popup shows normally, when you click on the login button. 

Any suggestions on how to address this issue?
Thanks & regards,
Agnes 



div#login-modal.modal.in {
    display: block !important;
    background-color: #FFF;
    top: 5%;
    position: fixed;
    left: 50%;
    z-index: 1050;
    width: 560px;
    margin-left: -280px;
    height: fit-content;
}

 

Hi Alex,

And it worked like a charm! What a service,
Many thanks,
Agnes