EDIT: solved, this is now a bug report. See the first reply for details.

This could really benefit from more detailed instructions, because I dont know how to tell what's going wrong if I don't know what's supposed to happen. I'm sending the signal "Mining Productivity" on the red wire to the tower with a value of 1, no research is currently in progress, my mining productivity level is currently 234. Nothing is happening.
The research analyzer seems to function just like a constant combinator as well and isn't outputting any level or cost data.

I'm on Factorio 2.0.66 using Krastorio 2 Spaced Out, a few planet mods and some QoL tweaks but nothing else that changes or controls the research queue. (I am using Castra, in which the enemies have a similar but separate research tree but it doesn't seem to conflict with mine)

Okay, I did a bunch of testing and found that the tower works fine while on the ground of Nauvis, but is functionless when placed on a space platform. This causes difficulty in Krastorio 2 Spaced Out because the endgame science labs in that mod can only be placed on space platforms, so the best place for the tower is where it can be given a signal based on the inventory available to those labs.

I'm working around this for now using the AAI Signal Transmission mod to report the inventory of the space platform to Nauvis and determine the research target on the ground.

I am unsure why it is behaving that way there is no reason why it would not work in space, all of the functions are universal. My first thought was make sure you are using normal quality for both the tower and analyzer as neither will function at any higher quality.

I am, I made only one of each entity and the same ones work just fine on the ground. I tried disabling most of my mods and still was not able to make them work on a space platform. Other research control combinator mods have the same problem. Have you tested it yourself?