Red rectangle in Unit Grid Cell on Map Setting

Hi guys ,  I got a huge problem on roll 20 setting's map. when i try to ajust my map setting for grid / cells value, no matter the number i try to get, i can't half value. No matter i enter a "." or "," the system say it's a wrong value by a red rectangle. 1.5 ou X,x  doesn't fit , i don't know why . No matter the map , the size, the dynamic light or fog of war .  Any Help ?

When you hover the mouse over the red rectangle, it says the nearest valid values are whole numbers. So it looks like that field does not support decimal values.

Thks for ur help , but i think the problem is somewhere else. Because with an plus account i can fill it , but a friend with an Pro account can't. Any other Idea

Hello Shura, I have taken a look and can reproduce this in Firefox but not Chrome. As a work around, can you verify if you have this issue in Chrome? I have gone ahead and passed this information along to the devs. We hope to have additional information for you soon.

Thank Dragon Dreamer,  It was indeed a bug with Firefox only, Chrome and Edge works fine .  Thanks a lot,  i've tryed to change my account default language but same with Firefox.