24 hours is very little time, I prefer a week at least. I had the same problem when using primer for synthetics/ metal the first layer. I used this for my carbon arrows. I finished it with two layers of normal enamel paint, but no matter what glue I used, the glue kept melting the paint away. It almost drove me crazy. I think it is caused by the anti corrosion component in primers for synthetic/metal.
In the end I used fletching tape, and that worked out perfect. No issues at all, no melting and the tape holds the fletching rock- solid!
For getting a clean line, I use paper painting tape. But....... It is critical when you take the tape off. When the paint is fully dried, you damage the clean line when removing it. When using paper tape, little pieces of the tape stay on the shaft, disturbing a clean line. The paint should be fluid, but not dripping anymore. So let's say halve dry
Now the tape comes much more easy off.
After removing the tape, let the shafts dry vertical, nock up. The not complete dried paint will gow down a little bit, camouflating not so clean lines. Once you got the hang of it, it's easy...