Which site? Choose another instance if yours is unreliable. That’s the advantage of a federated system. Or just have a second account at another instance.

There is https://www.goldencheetah.org/

It’s mostly for cycling, not too user friendly, not well documented, but very powerful once you figure out how to use it.

If you mean the European Health Insurance Card, it’s not the same as Universal Heathcare. If you travel to another contry that accepts it, you cannot go with any problem to the doctor, only ones that cannot wait until you return to the contry where you’re insured. Still useful to not have to have travel insurance within the EU, just might be useful to know.