I found the following users who may fit your language exchange criteria:

Username	Date	Post Link	Relevance	Offered Matches	Sought Matches
u/beneficial_camel_156	2023-10-28	Post	`8`	Russian (Native), Ukrainian	English
u/0oo7oo0	2023-11-02	Post	`8`	Russian (Native), Ukrainian (Native)	English
u/jmishonok_mishonok	2023-11-03	Post	`8`	Russian, Ukrainian (Native)	English
u/miserylovesblue07	2023-11-12	Post	`8`	Russian (Native), Ukrainian (Native)	English
u/specialist-comfort-6	2023-11-13	Post	`8`	Russian, Ukrainian	English

Please feel free to comment on the above posts to get in contact with their authors.