Sprinkler leaks pretty much take place as soggy spots, low force, or bubbling at heads

https://damientetu384.swiftnestly.com/posts/troubleshooting-low-stress-and-uneven-protection-in-sprinkler-systems

Sprinkler leaks frequently manifest as soggy spots, low strain, or bubbling at heads. Inspect risers, lateral traces, and valves, then restore cracked fittings to repair procedure functionality.