Shopify CLI: Wait - Compiling ... (hang)

Often changing my source code causes an immediate re-compile and the results appear directly in my app (via ngrok). Recently I have been having a difficulty.

wait - compiling / (client and server)…

node output in my console looks like this:

Running server…

┃ > [email removed] dev
┃ > cross-env NODE_ENV=development nodemon ./server/index.js --watch ./server/index.js

┃ [nodemon] 2.0.15
┃ [nodemon] to restart at any time, enter rs
┃ [nodemon] watching path(s): server\index.js
┃ [nodemon] watching extensions: js,mjs,json
┃ [nodemon] starting node ./server/index.js
┃ info - Loaded env from D:\Dropbox\0 sd\sdapp6.env
┃ event - compiled client and server successfully in 4.6s (1224 modules)
┃ > Ready on http://localhost:8081
┃ wait - compiling / (client and server)…

(and hang … hang … hang)

Running shopify CLI 2.18.0

Any ideas what is going on? I tried rebooting, restarting shopify app serve, and reinstalling the app on my development store. All to no avail.

Thanks! jb