The Doctor could swear sometimes that his TARDIS does things like this on purpose, developing faults or breaking down completely at the worst possible moments, just to inconvenience him.
She’s organic technology; surely she can figure out how to carry out maintenance and repairs on herself, but no; she grinds and shudders, making feeble, ultimately fruitless attempts to dematerialise before giving up, leaving him to fetch his toolbox and try to locate and fix the problem. It’s such a nuisance!
Maybe it’s her way of telling him she wants his attention. Or maybe she just wants him to feel needed.