Static on playback but not during recording

I am trying to record voice over on Audacity and am getting a static sound in the playback which i cannot hear during the recording. This is on the latest version, 2.4.1, on Windows 10 Home version 1803 on 64bit. The recording hardware is a Shure SM58 connected via an XLR cable to a Focusrite Scarlett 2i2 which is then connected to the laptop via USB.

Any help would be greatly appreciated.