help! bit chewing

[RedDiamond]

My 7yr old Welsh D chews the bit. She's done it since she was broken in but I thought she might grow out of it, which she has because she used to do it all the time but now she only does it when she's excited or nervous, like when we're cantering, jumping or if there's a bird hiding in the trees while on a hack.
Not only is this irritating to listen to constantly for me, but when she does it she doesn't concentrate on what she's doing and ends up tripping or spooking. Also as you can guess it doesn't make her look her best, ruining our chances of ever doing well at a show.
I've tried a flash, but it only made her worse. I've tried making her cheek pieces tighter but it didn't work.
Any help would be appreciated

 

[FfionWinnie]

Have you tried different bits? It has taken about a million bits, a dentist and a chiro and a Micklem bridle to shut up my gobby one...

I also have a Welsh Dx and while she doesn't chew the bit, she does so in times of irritation (like say I want her to stand still for more than a nano second!).

 

[kip22]

Chewing the bit is a good thing, shows they are relaxed in the jaw and accepting the bit. You shouldn't want to stop it. unless you mean in a frantic way in which case she may be finding the work you are doing to stressful, don't strap her mouth shut as that will just upset her more as I think you have realised, don't change her bit, just do some calming work with her, every time she chews frantically stop and walk until she calms. If there is no change after a few months, maybe a change in career would be the best. x