Strongholds does not generate in atleast some single biome worlds. I have done testing and can only conclusively say that in multiple single biome cherry grove worlds I have not been able to find any strongholds though eyes of ender leads to locations they would generate in if you have the same seed on normal worlds.

I have done some testing in other worlds and it seems to affect some or all of the nether and end biome single biome words as well and this is problematic because single biome worlds is ment to be beatable like any other worlds by design even though it may be harder on some setings. Stronghold generation works as normal if you use a deep dark world or a plains world by the testing I have done but I can not confidently say it always does.

Alternatively this could be 2 isues where one is that they do not generate in cherry grove biomes and the other that they only generate in overworld biomes even though they should generate in the overworld regardless of biome.

I can not conclude if strongholds never generates or if they only generates in a few of the places they are ment to. Sorry if I have missed some things or if my testing is not thorough enoug for your likeing but i have tried with limitrd rescourses to do the most important. And scense this is a pretty big problem I made a bug report now so it does not become a widespread problem.