fix(GODT-2822): event loop behaviour on 429.

internal/user/sync_downloader.go

@@ -379,3 +379,12 @@ func is429Error(err error) bool {
 
 	return false
 }
+
+func is429Or5XXError(err error) bool {
+	var apiErr *proton.APIError
+	if errors.As(err, &apiErr) {
+		return apiErr.Status == 429 || apiErr.Status >= 500
+	}
+
+	return false
+}

internal/user/user.go

@@ -778,7 +778,7 @@ func (user *User) doEventPoll(ctx context.Context) error {
 			}
 
 			// If the error is a server-side issue, return error to retry later.
-			if apiErr := new(proton.APIError); errors.As(err, &apiErr) && apiErr.Status >= 500 {
+			if is429Or5XXError(err) {
 				return fmt.Errorf("failed to handle event due to server error: %w", err)
 			}