Fledgling Eurasian Jay

Update: following the advice of Wildlife Aid we have put the fledgling back in a hedge and have our fingers crossed that we see them again!

Hi community, if you can please offer any assistance, I would be most grateful.

There has been a fledging Jay in the garden since Saturday, hopping around the garden and perching on the garden chairs. When my parents sent me a video of it on Saturday I didn’t pay much attention to it. Then on Sunday they said it was still around the garden. On Monday I began to observe it myself. What I think were the parents would like onto the bird feeder in the garden like they always do to take nuts, didn’t pay any attention to the fledging. The fledgling was sitting near by with its mouth opening and closing (like a feed me please action), they never fed it. They have been back many times since taking nuts but do not feed the fledgling. I spoke to RSPB and they provided a phone number of a local bird volunteer. I have been unable to speak to him as he doesn’t pick up my call but he kindly messaged to say that I should get some mealworms and small cat biscuits for the fledgling. For the last 2 days I’ve left some worms, the cat biscuits crushed and some berries out for the fledgling which it has eaten. I’m also really conscious that it needs to find its own food and for the least human intervention as possible. It can fly, I’ve watched it fly between the benches and garden table and chairs. Yesterday it flew up to the bird feeder table and sat in the round hanging tray that catches left over food, although I didn’t see it actually eating from the feeder. I asked the volunteer how long to expect it to be in the garden. I said I was concerned that it hadn’t flown away yet. He said ‘give it another day’, that was yesterday. I don’t know what to do for the best. I don’t want it to rely on the food that I am giving it but I’m also aware that the parents aren’t feeding it and we have artificial grass so not so many insects. As I mentioned previously it doesn’t seem to take the nuts or balls from the feeder. Should I continue to leave food for it? How much longer should it be in the garden for? Many thanks in advance.