PC exercise not working

[syvretp]

I find when doing the PC exercises i lose my erection especially after jelqing however in the morning i can kepp it going for a while and also after a joint when i get a hard on i can keep it going for ages.

questions are

is the losing the erection after jelqing common for beginners and will it actually get to a poiint where i can flex the pc muscle to produce an erection?

does it matter if you do the pc exercises in the routine or can you do them at separate times?

Thanks