Yet again, please don't manipulate place names for specific languages without consulting sources in these particular languages. "Volmari" was provided as alternative name ("alt_name:et") with a reason here. This name variant exists but it isn't common in modern Estonian, or rather is used only in historical context (see https://arhiiv.eki.ee/dict/qs/index.cgi?Q=valmiera&F=M). Hence it shouldn't be provided as the primary Estonian-language name.

Earlier we already had the same problem with Mazsalaca name: https://www.openstreetmap.org/changeset/68284694

Likely your changes to Polish name are unwanted as well here. Name "Wolmar", as per Polish Wikipedia, was in use until 2017. So "old_name:pl" tag probably was used with a reason.