Recently a plumber came and fitted a new pan connector to my toilet. It needed to be replaced and there was a sewage smell for about a week before it was replaced.
Since then the smell has reduced but hasn’t gone. And in fact is getting worse day by day.
Investigating it I found that the pan connector seems very loose on the back of the toilet. I can move and wiggle it with one finger.
I will post a video of it... https://youtu.be/X-4e2jS0ZW0
Could this be the source of the sewage smell? I presume it should be an airtight connection? So any amount of looseness will cause air to escape?