Regarding the original question:
fading is a phenomenon I encountered with kallitypes when I left them for too long in the (slightly acidic) sodium citrite developer, and/or cleared them for too long in citric acid.
I never had an issue with fading in the toner, and I imagine you might try to use a much stronger toning solution: for 20 drops of sod. pal. I consider a solution of 100 cc of 1% citric acid more than enough. In such a solution -50 cc is onough for an 8x10 - made to slosh over the image area, you see the toning action immediately, and the image is rapidly toned to visual completion - leave it for some time longer, though.
In the weak solution you mixed, the citric acid might iduce some bleaching even when the toning goes on - this is just a suggestion.