Hi,
Don't know if you can help, every now and then after flushing my toilet makes a strange noise. Like its coughing, however if I lift the lid to the cistern up, it stops. It also stops if I flush again.
A video is here , its louder towards the end.
https://streamable.com/8r8jmq
Image of inside the cistern is enclosed if its any use.
Thanks, Dan