No alt tags or title for gallery images

I installed plugin ticked all checkboxes (very nice settings page by the way), cleared cache, went incognito and they don’t display. I also deactivated Optimole image optimization plugin, but result was the same.

I made the following addition in plugin code to troubleshoot:

print_r($attr);
// Return the final attribute to front-end
return $attr;

Output looks good, but it isn’t applied to images:

Array
(
[src] => https://mledntqeqnnn.i.optimole.com/w:auto/h:auto/q:90/https://parymet.pl/staging/wp-content/uploads/2018/11/PARYMET-logo-e1554472606453.png
[class] => custom-logo
[alt] => Stainless steel standoff – satin finish
[title] => Stainless steel standoff – satin finish
)

• This topic was modified 5 years, 6 months ago by taisho.
• This topic was modified 5 years, 6 months ago by taisho.
• This topic was modified 5 years, 6 months ago by Jan Dembowski. Reason: Formatting

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