In addition to what others have said, this is definitely a failure of temperature control. Only some filaments will do more than turn liquid at temperatures that your print head should be seeing. (eg: PLA with hours of heat exposure)

If you never clean your print head (I always wire brush a nozzle before each print), it could just be buildup. Otherwise, I would take some time to check on what your printer thinks of a given temperature.

I’ve had to replace thermistors twice in the last 12+ years on my oldest printer (TAZ 6). Usually, it fails by being too cold and clogging. Though it has several times gotten too hot and produced similar results when it was going out or otherwise not thermally coupled well enough to the heating block. Rarely, it can be a connection issue between the controller and the thermistor.

Don’t be shocked if you have a few things to check and lock down before you solve the problem.