Why is my kitchen gully suddenly overflowing?

[MB23]

I reached in to try clear any obvious blockage, but all I could retrieve were a few stones at the bottom, I couldn’t feel an actual hole where the water goes out to so I assume it’s set up like photo 2.

I’ve noticed that sometimes the water sits at a constant low level whilst tap is on full blast, sometimes high, and recently on occasion is overflowing.

My kitchen sink has also started making a glug-like noise recently so I thought this was connected but after disconnecting all pipes under the sink for cleaning I found absolutely no blockage from inside, also stuck a snake up the external gully pipe on the wall that leads to my sink and found nothing at all.

Is it a blockage in a nearby manhole? There’s one within a few feet.

Would really appreciate any help anyone can provide.

 

[CBW]

What is the build up on the bottom of the gulley? Looks like either fat or sand and cement. Yes, a partial blockage by the sounds of it. Check the nearby manhole.

 

[MB23]

What is the build up on the bottom of the gulley? Looks like either fat or sand and cement. Yes, a partial blockage by the sounds of it. Check the nearby manhole.

It seems to be just small bits of gravel/stones, I pulled some out but it wasn't anything large. We don't put any fats or grease down our drain and never have since purchasing this new build 2 years ago, although it could be a hair blockages as the washing machine pump filter gets clogged ever so often. Thanks, I'll open up the closest manhole

 

[CBW]

It seems to be just small bits of gravel/stones, I pulled some out but it wasn't anything large. We don't put any fats or grease down our drain and never have since purchasing this new build 2 years ago, although it could be a hair blockages as the washing machine pump filter gets clogged ever so often. Thanks, I'll open up the closest manhole

I doubt it’s hair.