You can file a compatibility issue- via the 'Report broken site' option: see https://support.mozilla.org/en-US/kb/report-breakage-due-blocking- on webcompat.com (https://webcompat.com/issues/new), esp. if you want to include a screenshot)
@VladimirKart, support requests aren't allowed here. Please post your question with full details athttps://support.mozilla.org/en-US/questions/new/firefox/form.
