Top navigation won’t work

Dear all,

I’m working with the free version of The Events Calendar.
I can’t get the top menu working.

Here is what i did until now:
Added diverse css to child theme and customizer.
One at the time, tried both locations for custom css.
Here the css i tried, single one, and combined & mixed together.

.tribe-events-month #tribe-events-header .tribe-events-sub-nav .tribe-events-nav-next a, .tribe-events-month #tribe-events-header .tribe-events-sub-nav li,
.tribe-events-month #tribe-events-header .tribe-events-sub-nav .tribe-events-nav-next a, .tribe-events-month #tribe-events-header .tribe-events-sub-nav li {
display: block;
}

#tribe-events-header .tribe-events-sub-nav li {
display: block;
}

.tribe-events-month #tribe-events-header .tribe-events-sub-nav .tribe-events-nav-next a, .tribe-events-month #tribe-events-header .tribe-events-sub-nav li {
display: block;
}

None of the css or combinations on both locations works.
I work with WordPress, Avada theme and both including plugins are perfectly up to date.
Full option is set under settings Events Calendar, display.

Still on localhost for the moment.

Any help would be really highly appreciated.
Many thanks in advance.

Best regards,
Sven