Fortitude not working?

[MonkestationIssueBot]

Reporting client info: Client Information:
BYOND:514.1589
Key:azurachitin

Round ID:

4217

Testmerges:

• Behold, a Box!
• Isthisamap
• Steel Station, a new large station for the map rotation!
• [PORT] Custom antag objectives and a lot of changeling updates
• Fixes rev wins breaking the game
• Currently a TM PR for debugging
• Adds better trait for no stamina stun, adds it to various things that need it.
• Adds support for antag huds to only display to players with specific hud keys
• Artifact science stuff
• Shuttle gibbing code improvements

Reproduction:

Had fortitude on kept getting hit and as a result was stunned despite having fortitude on which says it SHOULD stop that? but it wasnt. Was playing as vampire

[NotACoderSorry]

The tooltip is unclear, but it takes higher levels of fortitude to get immunity. This is working as intended