The makers of dive reels and finger spools find themselves "between a rock and a hard place" as they say in cave country. Manufacturers know that for their devices to work properly, the line should only fill about 80% of the spool. Like a cup of liquid filled to the very brim, invariably an overfilled device will spill line back on itself and cause a jam on deployment. Then upon line retrieval, the diver has no hope of reloading the line as perfectly as a machine winder did initially, which means the diver is left with a bird nest.
So why do the manufacturers seem to often overload the spool? Because consumers, especially those new to using dive reels and finger spools, expect them be fully loaded to the brim and if they do not appear full the consumer may complain of being short changed or not purchase at all. The whole issue is compounded by the fact that most manufacturers don't use a line counter to load the spool, it's typically done by appearance not by measurement. Different workers will load line differently, but in general the tendency even in manufacturing is to overload the line plus packing too tight as a result of using machine winders. FYI, when you buy a reel or finger spool we loaded with our custom Hi-Viz line we use a line counter to produce a consistent load of the advertised length... but then even we load a little bit more; just to avoid consumer complaints about short loads.
The fix is very simple; if you are having a problem with jams or tangles on any dive reel or finger spool then try removing some of the line.