Clock.currentTimeNanos seems to behave differently depending on the compatibility_flags being used. This results in @effect/opentelemetry not properly assigning startTime for traces. Without the flag nodejs_compat, Clock.currentTimeNanos returns the correct value. But when using nodejs_compat, currentTimeNanos seems to start at epoch time (0 seconds). I found an issue in the opentelemetry repo that might be related to it: https://github.com/open-telemetry/opentelemetry-js/issues/5500 pnpm install and thenpnpm run dev and goto http://localhost:8787/ then check stdout in your terminalpnpm run dev-compat and goto http://localhost:8787/ then check stdout in your terminalClock.currentTimeNanos: 1745444706401999872 Clock.currentTimeNanos: 624000000