An error occurred while submitting your approval error in merge request approval

Hi, can anybody help? We have upgraded to 13.4.3 CE. After upgrade we are getting an error message: An error occurred while submitting your approval. at merge request approval. The error is
“exception.class”:“ActiveRecord::NotNullViolation”,“exception.message”:“PG::NotNullViolation: ERROR: null value in column “id” violates not-null constraint\nDETAIL: Failing row contains (null, 14237, 30, 2020-10-21 07:41:00.395674, 2020-10-21 07:41:00.395674).\n”,“exception.backtrace”:[“app/services/merge_requests/approval_service.rb:38:in block in save_approval'","app/models/application_record.rb:34:in block in safe_ensure_unique’”,“app/models/application_record.rb:33:in safe_ensure_unique'","app/services/merge_requests/approval_service.rb:37:in save_approval’”,“app/services/merge_requests/approval_service.rb:10:in execute'","lib/api/merge_request_approvals.rb:54:in block (3 levels) in \u003cclass:MergeRequestApprovals\u003e’”,“lib/gitlab/request_profiler/middleware.rb:17:in call'","lib/gitlab/jira/middleware.rb:19:in call’”,“lib/gitlab/middleware/go.rb:20:in call'","lib/gitlab/etag_caching/middleware.rb:13:in call’”,“lib/gitlab/middleware/multipart.rb:217:in call'","lib/gitlab/middleware/read_only/controller.rb:51:in call’”,“lib/gitlab/middleware/read_only.rb:18:in call'","lib/gitlab/middleware/same_site_cookies.rb:27:in call’”,“lib/gitlab/middleware/basic_health_check.rb:25:in call'","lib/gitlab/middleware/handle_ip_spoof_attack_error.rb:25:in call’”,“lib/gitlab/middleware/request_context.rb:23:in call'","config/initializers/fix_local_cache_middleware.rb:9:in call’”,“lib/gitlab/metrics/requests_rack_middleware.rb:60:in call'","lib/gitlab/middleware/release_env.rb:12:in call’”]
I would be really thankful for any advice