[en][ru] Does the extension work with uppercase in English only?

Regardless of the position of the upper case check switch in the extension, the error is not underlined in Russian. Is there any possibility to fix this? Thanks in advance for your reply.
(bicycle = велосипед, bicUcle = велАсипед)


I confirm the issue for Russian and Belarusian for the standalone version, snapshot of April, 26. Interestingly, Ukrainian is not affected.