I just encountered the same problem with the same error:
{"t":{"$date":"2023-08-23T23:31:04.280+02:00"},"s":"F", "c":"CONTROL", "id":20573, "ctx":"initandlisten","msg":"Wrong mongod version","attr":{"error":"UPGRADE PROBLEM: Found an invalid featureCompatibilityVersion document (ERROR: Location4926900: Invalid featureCompatibilityVersion document in admin.system.version: { _id: \"featureCompatibilityVersion\", version: \"5.0\" }. See https://docs.mongodb.com/master/release-notes/6.0-compatibility/#feature-compatibility. :: caused by :: Invalid feature compatibility version value '5.0'; expected '6.0' or '6.3' or '7.0'. See https://docs.mongodb.com/master/release-notes/6.0-compatibility/#feature-compatibility.). If the current featureCompatibilityVersion is below 6.0, see the documentation on upgrading at https://docs.mongodb.com/master/release-notes/6.0/#upgrade-procedures."}}
I did a quick google and followed some links but no solution was found.