Got a new widget from flag counter, and it's now https. Stuck it on my QRZ page below the old flag counter, and it works with Firefox. Only I'm down to one flag, and that one was me. Don't know of any way to restore my old country flags. I'll remove the new counter later.
This is how the old and new flag counters appear with Firefox...

With Dissenter, neither flag counter was displayed. They both worked as they should with Chrome. With Edge, this is what appeared...

Went to a couple of other sites where the flag counters were being displayed with Firefox. Noticed when I clicked on the flags, got https protocol. When I checked those sites with Dissenter, nothing was displayed. With Edge, all that was displayed was
Flag Counter as in the pic above.
So the bottom lines appears to be a new counter will display your flags on Firefox and Chrome, only you'll lose your old flags. Don't know about browsers other than those mentioned here.