Did you just run a test with Sauce Connect Proxy? Did your website or api fail to respond? Did you see "data" in the address field in the browser while the site attempted to load? Did your login animation loop endlessly after trying to authenticate?
If this sounds like like you then open up your sauce connect log and get ready to CTRL + F (or grep)! Wondering where your log file is? Check out Where is My Sauce Connect Log?
1. Open your log file up (or grep the below)
2. Get an idea of what HTTP response you're looking for (2xx, 3xx, 4xx, 5xx) https://developer.mozilla.org/en-US/docs/Web/HTTP/Status
3. Search for "<- 5" if you're searching for 500 status responses. The space after <- is required. <- indicates a Response to a request earlier in the log.
4. If you want to see the whole lifetime of a request first get your result from step 3, then look for the port number on the same line. In this example it would be 53006:
127.0.0.1:53006 (10.125.4.159) <- 200 somewebsite.com
If I was looking for 502 responses I would first CTRL + F for "<- 5" then look through the results for the domain I was testing.
You could also look for "<- 502" or "<- 502 my-site.com". The searching you do depends on what you're looking for. The log may be riddled with 5xx or 4xx responses if there's a network problem.