inNumberFrames of performRender is 1 in aurioTouch

aurioTouch sample codes runs OK on iOS15 devices, but on iOS16, inNumberFrames of performRender always becomes 1. On iOS15, inNumberFrames is usually 512 or 1024. Sometimes smaller or bigger, but not 1.

`// Render callback function
static OSStatus performRender (void                         *inRefCon,
                               AudioUnitRenderActionFlags   *ioActionFlags,
                               const AudioTimeStamp         *inTimeStamp,
                               UInt32                       inBusNumber,
                               UInt32                       inNumberFrames,
                               AudioBufferList              *ioData)`

I know aurioTouch is old sample code, but it runs OK on iOS15, so I suppose there should be difference between iOS15 and iOS16.

Any help on this issue would be appreciated.