They are an entry level machine designed to get you started with CNC.
They are very good at this as the makers have cut so many corners that from day one, nay, minute one you will be pissing about with this trying to get it running and stop the magic smoke leaking out.

By the time you have replace most of the components you will be time served and fully proficient at repairing CNC or at least know enough for your second build / buy not to fall into the same trap.

Regard it as a £300 correspondent course but one where the maker won't talk to you.