I use a dial rather than a digital. The main reason is that I’m too cheap to buy a digital one, but honestly, a hygrometer is a hygrometer. I use them not as a statement of fact, but rather a point of reference.
The important thing to remember is that hunidity in the tank, whether it be a plastic one or a glass aquarium, will have a gradient effect. The humidity will be higher the closer to the substrate/water source.
Heres an example. For my orchid mantids, I keep their aquarium at about 65-70, based on the hygrometer. Orchids require much more humidity, around 85-90, but mine have all done fine with molting and thriving. The humidity is actually around 85, but the hygrometer is at the top of the aquarium, so it registers the humidity to be much lower than it actuall is. I tried to get it to register a steady 85, and I basically poured a gallon of water in there, and I’m pretty sure that’s too much ?
So rather than trying to buy a new one, I would try to find out how inaccurate your hygrometer is, and go from there. It gets easier once you get the hang of it