Dropper post cable housing is separating from the black outer jacket. What’s going on here?

I only just noticed this today. The black outer jacket seems to be pulling away from the end of the housing. Looking back at photos on my phone, this started about a year ago and has progressed pretty linearly, with the gap growing larger and larger. The dropper lever action feels about the same as it always has. The dropper-end of the cable still looks fine. It's like the black jacket is shrinking somehow. What's going on here? Is the cable housing telling me it's inching towards failure and it's time for replacement?