Sandbox: https://codesandbox.io/s/cranky-kapitsa-op3jh

Repro: type "a" and then after a second "b"

Expected: Eventually you'll see "ab" in all fields. Pending "..." indicator goes away.

Actual: You'll keep seeing "a" in low pri field. Pending "..." indicator is stuck.
MutableSourceGetSnapshotFn,
  MutableSourceSubscribeFn,
  ReactEventResponder,
  ReactContext,
  ReactEventResponderListener,
  ReactScopeMethods,
} from 'shared/ReactTypes';
import type {Fiber} from './ReactFiber';
import type {ExpirationTime} from './ReactFiberExpirationTime';
import type {HookEffectTag} from './ReactHookEffectTags';
import type {SuspenseConfig} from './ReactFiberSuspenseConfig';
import type {ReactPriorityLevel} from './SchedulerWithReactIntegration';
import type {FiberRoot} from './ReactFiberRoot';
import type {
  OpaqueIDType,
  ReactListenerEvent,
  ReactListenerMap,
  ReactListener,
} from './ReactFiberHostConfig';
import ReactSharedInternals from 'shared/ReactSharedInternals';
import {enableUseEventAPI} from 'shared/ReactFeatureFlags';
import {markRootExpiredAtTime} from './ReactFiberRoot';
import {NoWork, Sync} from './ReactFiberExpirationTime';
import {NoMode, BlockingMode} from './ReactTypeOfMode';
import {readContext} from './ReactFiberNewContext';
import {createDeprecatedResponderListener} from './ReactFiberDeprecatedEvents';
import {
  Update as UpdateEffect,
  Passive as PassiveEffect,
} from './ReactSideEffectTags';