How do I fix cut-out vocals when recording with a Rode NT1-A and Shure SM58 microphone on my Macbook Air?

I have a new Macbook air 13" M3 2024 16mb - Mac OS 13.3.1 - I've recorded various songs, but recently when recording vocals via my Rode. NT1-A microphone, when holding a long vocal note, its tends to cut it short - ie not completing

Using a Focusrite Scarlett Solo interface

I've also tried this with a Shure SM58 with same poor results, therefore I don't think its the mics

I've also changed cables

all other instruments are fine

any advice please

Nigel

Marqueeclub

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