X_PWA_PUSH_PAYLOAD_TOO_LARGE
Means
the push message does not fit one 4096-byte record
Typical cause
the rendered notification (title, body, actions, url) serialises past the 3993 bytes RFC 8291 leaves for plaintext in one record
Fix
url: '/posts/1' — send a path to the content and shorten the catalog strings, never the content itself