Mastodon dns problem

[redegelde]

i have got an working DNS, if i test it, it goes to my vps running Cloudron.
now trying to install Mastodon it says did
Waiting for DNS propagation
and after an while error. What am i doing wrong.
do i have to put exact sub domain location here?
where is says location?
can that be the problem, i have left that one empty

regards eric