Just kidding. Two things. The tail, its my strong opinion, loss of tail tips and following tail parts if directly a result of extreme stress. Fortunately, it heals quickly if the stress is relieved.
As an example. I recently attempted to hibernate, hmmmmmmmm neglect, four young adult male mertens. Apart from one dying, and the other losing part of its tail. The other two being female and one of those laying eggs while being hibernated(neglected). All was fine, hahahahahha whoops back to your problem.
As soon as I discoverd the male having a tail tip problem, I turned up the heat, fed the heck out of them. And the dead parts of the tail have fallen off and the rest has totally healed and the three remaining mertens have returned to full health and are progressing rapidly. I remember there is a reason I hate hibernating(neglecting).
In this case it was lack of proper conditions that stressed the male. Causing loss of tail parts.
Other things that can cause that type of stress and resulting tail lose is, social stress. If the wrong individual monitor is in with them, they may not fight or show any overt signs, other then the tail falling off.
Lastly, conditions that are not suitable to the species. I believe this may be your problem. Albigs are desert, draining soil type monitors. They do not want or need to be humid. To much humidity(closed in moist air) can stress the heck out of them. And it also causes thickening of the skin, and terrible sheds and terrible skin condition.
I believe all monitors, require a stable humidity, not high and not low. And humidity that controlls dehydration. Something around 40 to 50%, in the burrows. With open air humidities much much lower, like in the 20 to 30% range or less. Heck, I do not worry about air humidity what so ever. As long as they have stable burrow(hides) humidity. Under conditions that do not dehydrate them, they have no use for water, to soak or even to drink(hard to accomplish with our sucky cages) They normally get all the moisture they need from their food.
Please do not confuse this with, THE BEEF JERKY EFFECT. that is rapid air movement from hotspots drawing the moisture out of the monitors and anything else in the cage.
So my guess is, toooooo much moisture and toooooo much concern for such. Both symtoms can lead back to, to much humidity. So there you have it, hahahahahahahaha I wish you luck in returning your monitor back to full health. Cheers
But then, I have no idea of other conditions that may also be a cause.