That’s what I read In the manual to do charge it properly first with wired performance that’s all it says about it.You've got a couple of separate issues going on there Gel.
You're right to ensure plenty of charge before judging the wireless performance.
But, I would have thought (would certainly hope) that charge level would be irrelevant for wired use.
Concentrate on anything in the user manual that deals specifically with going between wireless and wired.
I have tried it with an adaptor and without it still no luck.Don't you need the USB-C to 3.5mm headphone adaptor (or lightning to 3.5mm adaptor if older iPad) to get an analogue out signal? Each of these is £9 at apple shops which must be a record low price for an Apple accessory.
I have a first and second generation iPad Pro 12-inches and yes they have the headphone output socket on them. I have also tried with the Apple adaptor on them but no luck.Which generation and type of iPad have you got?
Has it even got a headphone out port?
But yes the obvious thing is to fully charge the headphones first.