Browsersync stuck loading when proxying Trellis local dev site

[strarsis]

I also encountered an CORS-related BrowserSync issue in the past - could this help you?:

Sage 9 + BrowserSync not loading any CSS at all on 'yarn run start'

@Simeon: Edit: According to author BrowserSync has to be configured with advanced key: new BrowserSyncPlugin({ target, open: config.open, proxyUrl: config.proxyUrl, watch: config.watch, delay: 500, advanced: { browserSync: { cors: true, }, }, }), Related issues:

What Sage theme version are you using? If you are using Sage 9 you may find the Sage 9.x update branch interesting which fixes a ton of build/watch issues:
https://discourse.roots.io/t/sage-9-1-please-test/20067?u=strarsis