Discover a solution and posting for anyone who has a similar issue.
Within the figma desktop app there is an Interface scale feature. Found here View > Interface Scale
Which you can scale the interface to be larger or smaller. Had the interface scaled down, reset to default to fix issue. View > Interface Scale > Reset to Default
Fonts now the same as in browser.
While this feature helps to reduce the interface size, as a user would not have expected it to scale the canvas and its frames/groups etc so that they are not truly reflective of their zoom level. Would have expected the zoom level to control that so it always looks like you would expect when designing for whatever size. It’s very frustrating and resulted in a quite a bit of work to fix.
Cheers