You need to also flash VBmeta.img along to recovery.img
sudo heimdall flash --VBMETA /path/to/vbmeta.img --RECOVERY /path/to/recovery.img
You are right, it should not be possible over P610XXS4FWK1 (where k for november),
Best is to downgrade to P610XXU4FWJ1
This /e/OS v1.17 includes the Android security patches available until October.