Have you encountered any bugs in Warframe?
Check the list, and leave a comment.
~1 Luminescent Dye sometimes make fish spawn slower, or stop temporarily.
~2 Un-equipping and re-equipping your fishing spear after throwing out your fishing bait negates the effects of the fishing bait.
I've tested this a few times, with different fish, each time gave the same results.
When I equipped my spear, threw my bait, and fished for the whole time of my bait, i'd find 4-8 of the rar