Question regarding ordering on bloomwell

Hey guys. Sorry for my post being in English.

Last week i decided to try out bloomwell and get my weed from an apotheke. Everything went well and I ordered 5g of huala 27/1 ca alm. It was pretty good.

Now since I am done with my 5g i went to order again but it's not letting me order 5g and the minimum buy is 10g now and I have to get another prescription. Is this normal? Can I not just buy only 5g instead of 10g? Can someone explain.