deptfed

The flush mechanism in the concealed cistern of my toilet will not stop dripping - I have removed the mechanism, cleaned it thoroughly to remove any limescale, and replaced it with all notches lining up correctly and the ring screwed very tight. This slightly reduced the dripping but it is still dripping once every few seconds. Video and image of parts is attached - would really appreciate any advice on parts to replace or other things to try. IMG_3031.MOV

Thanks all for the responses! I've added a couple of photos here to show the whole set-up as the trap below seems like it could be relevant. From reading the suggestions I think I will try taping it up first (seems like no harm in trying the quick fix), and if not then I'll have a go at creating a solid connection like @MJNewton suggests.

The MVHR in my 4-year old flat has started making an intermittent gurgling noise in the outlet pipe below it, which is loud enough to be heard through the vents in the rooms. It tends to be more noticeable during the day rather than the evening/night, and doesn't happen every day. I've attached a video as the sound is hard to explain - it sounds like a gurgle of water in the pipe. If you block the pipe coming down from the MVHR unit with a finger then a) the noise stops and b) your finger gets wet. Does anybody know what could be causing this and if there's a simple fix? Model = Titon HRV1.25 Q Plus Eco TP406HMB MVHR_Gurgling.mp4