We didn't notice this to be a problem until I tried creating a player character stat block template and sharing it with my players- they cannot see the stat block template, and when I started researching that in the help/learn pages, I saw that the RPG system is required to be correct. My campaign world is created using the 'Shadowrun 3rd Edition' RPG System, but my players confirmed that they do not see any choices starting with Shadowrun when they try to edit their characters.
add a player character to a campaign using Shadowrun 3rd Edition
attempt to set the RPG System on the player character to match the campaign
https://www.worldanvil.com/sheet/1692005/view
https://www.worldanvil.com/heroes/campaign/0a435ee4-0335-48c4-a11b-6fc8b7af0cf6/dashboard
Hey, this RPG system hadn't been marked ready to use by players - I have done so and they should now see the option to connect it to their characters. Please let me know if this resolved their issue so if it's still happening.
Apologies for the delay in response, but it took a few days for my players to get back to me- this is confirmed fixed now. Thank you for the quick turnaround!