Monk and Paladin physical resistance loss

Hello,
i have the following problem: After a certain time, the physical resistance of Monk and Paladin decreases. As i was unable to slove this problem, i would be glad as someone could help me to find out the reason for this.
Thanks a lot in advance!
i have the following problem: After a certain time, the physical resistance of Monk and Paladin decreases. As i was unable to slove this problem, i would be glad as someone could help me to find out the reason for this.
Thanks a lot in advance!