Bangla (Bengali) translation for "hour" is misspelled in DiscussionTools visual enhancements, according to the report by @Aftabuzzaman here: https://www.mediawiki.org/wiki/Topic:X25x1ejl3zfo5h2y
Unfortunately, on Wikimedia wikis, the time formatting doesn't use usual MediaWiki localisation messages, but rather data from https://en.wikipedia.org/wiki/Common_Locale_Data_Repository. This means we can support more languages, but fixing mistakes is more difficult.
They reported the problem at https://unicode-org.atlassian.net/browse/CLDR-15975, but it might take a few months before it's accepted, and then more before we update our version. Perhaps we can do something to fix it quicker.
By the way, MediaWiki's own translation was similarly corrected in 2014: https://translatewiki.net/w/i.php?title=MediaWiki:Hours-ago/bn&diff=5588747&oldid=4720191