Coward's Legacy does not work with Hardening Uulgraft

Coward's Legacy unique belt said:

"

You count as on Low Life while you are Cursed with Vulnerability
You are Cursed with Vulnerability

Hardening Uulgraft skill "Tender Embrace" said:

"

While you are on Low Life, this Graft will periodically apply a buff to you which grants life recovery rate, as well as an Endurance Charge.

So, according to the description, when the belt is equipped, the "Tender Embrace" should be constantly active and periodically provide a buff, since the "be low life" condition is always met.
However, this doesn't happen until the actual HP is reduced to the required level for "low life," and if you maintain that level, the "Tender Embrace" will work constantly and periodically provide a buff, as expected.

I don't have any curse immunity; the vulnerability curse is active.

I also expected this interaction to work and am disappointed to find this is bugged