This was a major issue since v4 was introduced but should be resolved now, try updating.
Relevant issue with other workarounds: Population does not work for Users in Users-Permissions · Issue #11957 · strapi/strapi · GitHub
This was a major issue since v4 was introduced but should be resolved now, try updating.
Relevant issue with other workarounds: Population does not work for Users in Users-Permissions · Issue #11957 · strapi/strapi · GitHub