Hello, Blagovest,
xstore-core-bg_BG.po and xstore-bg_BG.po are correct names, files with other names can’t work and may cause problems, so delete or rename them – https://prnt.sc/oNlIDADgThTO https://prnt.sc/_fcxpglm60PG
We hope this information is helpful.
Kind Regards,
8theme team