Sort & filter buttons are (suddenly) not available in Excel table

I have an Excel Table (created by CTRL+T), where filter buttons are added by default. But suddenly they disappeared and the checkbox for switching them on/off is greyed out.

There are two other tables in same sheet and they work properly. I can't figure what causes this behavior.

Sceenshot:

Copying sheet to another/new workbook doesn't help. How can I stop this from happening?

Solution 1:

I had the same issue. When I turned "header row" off and on again they reappeared. (Yes I am congnizant of the fact that it sounds like a fix to every other MS apps issue... but it actually worked for me.)

Solution 2:

Select all of the headers, go to Home>Sort & filter> and make sure the filter button is selected in this option. That should fix it for you