Without knowing more, it probably falls into the "it depends" category.
If the electronic dys / mal -function could result in patient harm then just documenting it is probably insufficient (for mitigation - and bear in mind the harmonized version of 14971 doesn't allow risk reduction for just documented controls).
If it doesn't result in any patient harm but the user has to do something to get the system operational again, then yes, having something in the manual is probably warranted.
If your question of dysfunction is trying to address any random failure and the user detects it (no display, obviously erroneous operations, etc.) then maybe just a generic statement to contact customer service (or whatever is appropriate).
I'd say that documenting something falls pretty low on the effectiveness scale, for whatever reason it would be documented. But there are obvious cases where it at least should be done.