Some layers show in AGOL but not Collector

[DeanMiller1]

Hi all, I'm configuring maps to show the location of water utilities for field operators using iPads. I'm having some issues with a couple of layers not showing. The layers that don't show in Collector show just fine in AGOL. The example in my screenshots below shows the green Stormwater_Node layer showing in AGOL (right screenshot) but not in Collector (left screenshot). Another similar layer in red, with some similarities in symbology and attributes etc. doesn't have this problem. Can anyone please advise on the most likely issues that could be causing this, and I'll try to do some troubleshooting.

The maps are set up for offline use and syncing. Thanks for any assistance.

[BertKraan1]

Have you re-saved the webmap after the last changes to the feature layers? We've had some issues with that. After resaving the webmap log out and back in in collector.

Are all the layers read-only? I cannot get that to work either.