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

Username	Date	Post Link	Relevance	Offered Matches	Sought Matches
u/essaytop352	2021-04-02	Post	`7`	German (Native)	English, Russian
u/guerkchen95	2021-02-09	Post	`5`	German	English
u/orangecatmeetsmatcha	2021-01-28	Post	`5`	German	English
u/rouladentrash	2021-03-17	Post	`5`	German	Russian
u/ml_observer	2021-02-19	Post	`5`	German	English

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