The biggest churches with most followers,
like Orthodox Christians, Roman Catholics, Protestants, Anglicans, ...
didn't and don't claim the Earth is flat.
Where religion in involved it is small, newer churches that used
the claim that Earth is flat for their own purposes.
Some followers of big churches also insist on Flat Earth,
but they are rather exceptions in small percentage.
In Islam the percentage is bigger as is their influence.
When sheikh Hamad inheritedt that island, and carved canals in sand
to make his name readable from satellites in space, they ordered him
to remove it quickly.
Was it because people there must not doubt their
claim that "satellites, or even Space, don't exist"?
I didn't see the official explanation given for that removal.
"HAMAD" ERASEDWhere religion is not involved, I can only guess.
For example:
"Person either really believes, and struggles to make it viable,
or rejects everything mainstream and wants to change it,
or hated science teacher and still wants to prove them wrong,
or doesn't know, but believes, and 'defends oppressed and manipulated minority in fight for truth'..."
Or doesn't believe at all, but makes videos on YouTube about what Flat Earthers want to hear, to use them for personal gain.