Bluetooth audio plays slower after upgrade to Catalina

I have an early 2015 Macbook Air that I connect to a Panasonic SC-PMX92 audio system via bluetooth.
I recently upgraded the OS from Yosemite to Catalina and since the upgrade the audio playback on the audio system is broken.

Initially I thought that the issue was just bad latency, but after some more investigation it looks like somehow the sample rate has been "lost in translation" – I can play a 1kHz test tone (e.g. https://www.youtube.com/watch?v=3FBijeNg_Gs&t=15s) and the tone out the speakers is ~919 Hz (tested using a chromatic tuner). 44.1 kHz / 48 kHz * 1 kHz = 918.75 Hz. Coincidence, I think not!

The audio system supports AAC and the bluetooth icon indicates it is using AAC.

What I have tried:

• Reset the SMC
• Set "Enable AAC codec" = 0; (this didn’t appear to have any effect)
• Forget all bluetooth devices and reset the bluetooth module

EDIT
Looking at Audio MIDI Setup I can see the format is only 48 kHz, which is strange because the system supports up to 192 kHz. I’m still not sure if this is a Catalina error or an error with the audio system, however the audio system doesn’t have any firmware updates and the output worked in Yosemite (but I don’t have any before pictures)