Computer Lags when Exporting

Version 2.5b (1118)
When I’m exporting fonts from Glyphs App, suddenly my music stops playing over airport – wondering if anyone clues about this issue.

macOS 10.12.6 (16G1114)
2.3 GHz Intel Core i7
16 GB 1600 MHz DDR3

Autohinting and subroutinization can be very processor-intensive. But it should not affect wireless connections, because it requires no networking. Therefore wondering if there is a second factor involved.