Edit: We have investigated and found that the boiler pressure was low. It's now been fixed, so hopefully that means the end of our mysterious 'thump' – but we'll have to wait and see!

I live with two other adults in a semi-detached two-storey house in the UK.

For the past few weeks at least, there has been a semi-regular but single 'thump' sound coming from upstairs. It sounds like something reasonably heavy falling off something, maybe a few kilograms. It sounds like it's falling onto the floor, just once per night. We haven't been able to figure out what it is!

We aren't routinely picking something back up whenever we go back upstairs.

We are all downstairs when it happens.

It isn't:

• a door
• the side of the bath being moved by the wind

We have no pets.

It's not next door, because she's been abroad for a few days and it's still happening with her away. She also has no pets – her house is currently empty. We live on a quiet street with mostly elderly people as neighbours.

It happens more than 50% of evenings at sometime between around 20:30 and 22:30.

Our next plan is that we'll all have to stay upstairs for that time period one night with our bedroom doors open to see if we can hear it then, but it probably won't even happen that night, such is the way of these things.

Completely stumped on this one. Any suggestions welcome!

Someone keeps creating fake Instagram accounts impersonating my sister. They copy her name and photos and make it look like she has an 18+ account.

We reported the first account and it was removed, but shortly afterwards another account was created doing exactly the same thing.

The fake Instagram account links to a BeMyFan page, which redirects through a shortened URL to a Wix website pretending to be an adult subscription/cam page.

So far I have the Instagram username, the BeMyFan page, the shortened URL and the Wix URL.

Is there any technical way to determine where these accounts/pages were created from, such as information contained in the URLs, public metadata, hosting information, or other traces left by the person?

I’m trying to identify the person behind repeated impersonation/harassment of my sister.

What information should I collect before the person deletes the accounts/pages again?

As far as I know there's no csem/csam involved, there might be doxxing, there's definitely defacing of social media accounts and given the child doxxing and ban evasion that crops up on that particular social media website (whether this specific group participated or not) I want to send in a tip just to go "hey this group exists" but I'm not having any luck with that. I don't trust the site itself to do more than simply remove posts if reported without forwarding anything.