What are these called?

They are gas struts and are used for top hung doors. When a door is top hung using them, the weight of door itself cause it to close properly.
If you get some of these: https://www.amazon.co.uk/Blum-38C315B3-Blumotion-Degree-Restriction/dp/B06XRTSNGP?th=1 and remove the gas struts, your hinges self close should work like normal.

 

They may or may not work with your current hinges. If they don't all you have to do is buy a pair of hinges listed on the link.
To save any stress on a single hinge, i would use one on each hinge.

 

Can you do a decent close up of teh hinge fitted - and in focus. And also with any name overlay removed.

You may be able to use an insert or change the actual hinge. What ANGEL do you need to restrict to?

 

Don't know of a Blum hinge that will do it ... but there is a combination that will get close:

Use a 71M2xxx which is a 100 degree hinge https://publications.blum.com/2020/catalogue/en/84/

Use a restrictor to bring it down to about 85 degree

Then put in a 5 degree spacer https://publications.blum.com/2020/catalogue/en/162/

Call Blum Technical 01908 285700 with the existing hinge type and see what they say. Always helpful when I have called with niggly problems

 

Put my suggestion to them and see what they say ... then let me know as it is always worth knowing. I have a door which uses 100 and a restrictor to get 85 degrees to miss crashing into a rack - just; the other door is a 170.

We had a local Blum distributer- whith almost every hinge available ex-stock and they had a pallet or two of hinges and associated products delivered every week so you could go and try everything until a solution was found.

 

So that will give you the 86 degrees - what about the 5 degree spacer for getting closer to 80?