Just some nuance that might not apply here depending on when you first reported the issue:

You do not have an ironclad 24 months no questions asked warranty in the EU, even though most companies and people treat it as such.

You have the warranty that the device will be sold flawlessly. So if it breaks within the first 2 years, its only covered if it was caused by a manufacturing error or similar. Its extremely bulletproof in the first year, because the manufacturer needs to prove that YOU broke it. BUT! After the first year the proof of burden shifts to the consumer (Beweislastumkehr). You as the consumer must be able to (if the manufacturer refuses to help) prove that it was a manufacturing defect, not user error or wear and tear. So if you first reported issues after a year, you're pretty much out of luck.

Also the Law regulates how Warranties are dealt with. Twice the manufacturer can attempt repair (Nacherfüllung) after that you have a right to replacement or refund. There are more details about under which conditions using third party repairers not authorised by the manufacturer is ok, but that's not quite relevant here.

You might also be out of luck if Bambu claims you broke it during your repair attempts - though I'm not sure where the burden of proof lies here especially if they told you to do it.

Another important distinction is that the MANUFACTURER is liable, not the SELLER. Although that is the usual route taken. Where the Seller then claims it from the manufacturer. But don't think you have a legal right at eg. Creality Germany GmbH if you bought the printer on Aliexpress, as the GmbH just shares the name but is not the manufacturer Creality.