I have a 3DWOX 1, and I have encountered the same problem, but only when using one particular cartridge. What seems to happen is that the one or both of the rubber rollers slide longitudinally along their axles, to the point that they rub against the supporting plastic moulding, giving a large increase in friction. It can also happen that they move so far the filament is no longer gripped properly between them. I find I can work them back into position easily enough, but they don't stay there - I am investigating glue.
For me, this has only happened on the 'two-roller' cartridge design, which has two rollers gripping the filament and a single, small-diameter driving gearwheel. My original cartridge was a 'three-roller' design, which has a larger diameter driving gearwheel & driven roller, and a third, geared roller driving the flange of the filament spool, presumably to help rewind the filament when changing cartridges. This doesn't have the same problem, but it does tend to break filament when the spool is nearly empty, as the flange drive inevitably can't be correctly geared for the changing outer diameter of the filament coil as the spool empties. To avoid this, I unload the cartridge and manually loosen off a few turns before each job, when the filament is running low. Which is a pain. Presumably that is why Sindoh changed the cartridge design.