Bluetooth keyboard lag with 7th Gen iPad

Hi,

I have recently bought my daughter a compatible bluetooth keyboard (Logitech Slim Folio) to work with her 7th gen iPad. It connects OK, but each keypress required around a 2 second press to get a key to appear. I have reset the network and dictionary settings, soft reset, deleted and re-added the device etc. all to no avail. I have even tried two separate Logitech Slim Folio keyboards and they both have the same issue. I also have a Logitech bluetooth keyboard I use with my Mac and that works perfectly, so I connected that to the ipad and the same issue, leading me to think that the issue is with the ipad.

It states that it is compatible with this ipad, so should work. Does anyone have any ideas of what else I can try?

Many thanks,

Graham