Sometimes I have to leave my favorite flavors alone for a couple of days. Then when I go back to them, I can taste them again.
I think it maybe also helps if you have a couple of different kinds of favorites. Like, I noticed yours were both fruit flavors.
I have three main favorites. One is kind of a minty one, one is "Orange Strawberry Ice" and the other is "Ivory Bliss" (a combination of white chocolate, almond and raspberry).
If I vape on Orange Strawberry Ice for a while, the flavor seems to be less intense, even when I keep a glass of water next to me and vape, sip, vape, sip, etc. So I'll switch to my minty one and vape on that for a while. Then switch to my chocolate one for a while. Eventually I'll come back to the Orange Strawberry one and I can taste it again.