Factorio Forums

If the player installs a mod they find handy but do not yet want it enabled, they have to restart the game for it to show in the manage list, disable it, then restart the game again. More of an incompletely implemented feature than a bug, as it runs counter to the ability to update, install, and enable/disable all desired mods in one session prior to restarting the game.
Recommended action: Newly installed mods should immediately appear in the manage list so that they may be disabled if desired.

Thanks for the report. This is a known thing that will be addressed at some point.

This is alos true for updated mods. I just updated from 0.16.x to 0.17.4 . 8 of the 20 installed mods had updates which made them compatible with 0.17.x . After updating those mods, none of them showed up as compatible and usable in the manage tab. Just after a restart they are displayd correctly.