Help our beagle is acting strange

Im not sure if anyone could offer a little advice?, our beagle who is 14 weeks old seems to wee slightly when over excited, which is expected but also for some strange reason when we open the back door for her to go do her business in the garden???, The reason im a little perplexed is that when we have the door open on a nice day she freely goes in and out at her own pleasure, now I knoe beagles can be stubborn but its so difficult, especially when were about to pop out so we open the door for them to go to the toilet before we leave them, and she seems to cower and put her tail between her legs and if we try to comfort her she wees on the floor, i thought it might be because she knows were going out but it seems she does it at night before we go to bed when we let them out for their last toilet stop. Its frustrating because we cant understand why she does it, we don’t smack her, we don’t shout at her, we sometimes sound stern if were telling her no to something but that doesn’t seem to bother her much, its only when it comes to going outside, yet when the doors open she freely goes out and also she sometimes goes straight to it and whines so we let her straight out and she does her business????
Has anyone else had this problem, or does anyone have any advice on how to change this?

it does seem a bit strange. try showing her the back door and garden doesnt necesarily mean she has to go to the toilet. maybe open the door and call her through it and play with a toy outside or reward her for going out? hopefully someone will come along with better advice but it seems like shes doing it because she knows you are expecting her to go out and do a wee.

Thanks it is strange because she will go out on her own accord but when we need to let her out say before we go out or if its a particulary a nasty day weather wise, and we need to keep the door shut, she doesnt always ask as she hasnt fully learned yet, and being so young her bladder actions are more frequent lol