Vauxhall Meriva starting

Intermittant non starting cranks but doesn't start.
Seems to do it after heavy rain high humidity.
Engine spanner light on. No fault codes.All self test lights come on go off. New battery coil pack last month after other ignition problems.
Sometimes over cranks after key is released as though the ignition switch immobiliser is an issue. If I leave it a while it will start or has done, Currently stuck waiting to see if breakdown service can get it going. Any advice pleas. i have had so much electrical problems with this car it will be nice to back to a classic car.