Directory template - multiple repeated letters

Hello

When I select directory as general template I can see a of of duplicated letters.
Please look into attached photo. Is this a bug or feature?
Should there be only one of each letter?
Or preferably only letters from existing listings.

Extension - GMapFP - Plugin 3.0.0 May 2010 extension
GMapFP Article - Administrator Component J3.116P Mars 2018
Map for Pro GMapFP - Site Module J3.7Pro Février 2015
Joomla 3.8.8

Regards

Hi

Yes, this fixed issue, thanks for suggestion.
Is it possible to have URL ALL which displays all items, before A B C D urls?
All A B C D .. etc.

Thanks
Regards