Wrong format: thousands separator

Hello,

I used the plugin “Post Views Counter” and it displayed fine counter with the thousands separator as a dot (.).

But after I updated WordPress from version 4.9.15 to version 5.6 counter did not display correcty anymore. The thousands separator becomes comma (,) instead for dot (.) e.g. 4,500 instead of 4.500

If you visit my site: you can scroll down and see counters on the right column with the following numbers after the most viewed posts title. They are numbers: 3188, 2020, 1637, 1247 and 1224 in the parentheses with black color.

Do you have any advice to me?

Thanks in advance.

The page I need help with: [log in to see the link]