Saw something similar to this in an earlier topic, but it seems it wasn't fixed entirely.
Evolution still can't quite reach 100% with certain mod setups.
I'm currently running an Angel+Bob setup, and in my test world (which has all non-infinite techs researched), evolution has capped out at 98.53% (according to EvoGUI, or 0.9853 according to /evolution).

Also want to comment to this, would really like it if the evolution can reach 100% because the mod Endgame Evolution as example spawns really hard biters in the last 0.1-0.01 %. With only reaching 98.5% i miss out about 30-40% of the feature of the Endgame Evolution mod. (Endgame Evolution Mod Link https://mods.factorio.com/mod/SchallEndgameEvolution)

Apologies. I hadn't subscribed to all threads for this mod. No idea why that wouldn't be the default for mod owners, but the upshot is I hadn't seen your bug reports.

Now I'm aware of it I'll take a look. Some extra info would help:

Are you on 0.17?

Could you provide a complete list of mods (quickest way can be to upload your save and I can sync it to debug)?

Yes this was on 0.17.
Made a fresh save (because my normal test save has a few personal mods, though none of them override any techs, and only one adds any tech at all) and unlocked all tech with the Creative mod: https://www.dropbox.com/s/p4rj9mvyotwquvy/evo%20bug.zip?dl=0
I apparently had added more mods since, because evo capped at ~97%.
...Also, I just realized I accidently enabled one of my personal mods... When syncing, make sure to disable "NS-roboports". It shouldn't impact things at all as it doesn't add or remove any techs, though.