I took all the steps again you recommended above, including adb commands. After I move the slider to OFF and confirm it, as soon as the PIN entry screen disappears the slider can be seen instantly sliding to ON. Here are what seem to be the relevant log entries:
--------- switch to events
05-01 21:11:00.624 29485 29485 I wm_on_top_resumed_lost_called: [Token=89953786,Component Name=com.google.android.gms.constellation.ui.ConstellationConsentSettingActivity,Reason=topStateChangedWhenResumed]
05-01 21:11:00.649 29485 29485 I view_enqueue_input_event: [eventType=Motion - Cancel,action=com.google.android.gms/com.google.android.gms.constellation.ui.ConstellationConsentSettingActivity]
05-01 21:11:01.525 29485 29485 I wm_on_paused_called: [Token=89953786,Component Name=com.google.android.gms.constellation.ui.ConstellationConsentSettingActivity,Reason=performPause,time=1ms]
--------- switch to main
05-01 21:11:01.560 29485 29485 D VRI[ConstellationConsentSettingActivity]: visibilityChanged oldVisibility=true newVisibility=false
--------- switch to events
05-01 21:11:01.573 29485 29485 I viewroot_draw_event: [window=VRI[ConstellationConsentSettingActivity],event=Not drawing due to not visible. Reason=!mAppVisible && !mForceDecorViewVisibility]
05-01 21:11:01.577 29485 29485 I wm_on_stop_called: [Token=89953786,Component Name=com.google.android.gms.constellation.ui.ConstellationConsentSettingActivity,Reason=STOP_ACTIVITY_ITEM,time=1ms]
--------- switch to main
05-01 21:11:02.190 28754 29506 I ActivityScheduler: nextTriggerTime: 22559917, in 21804ms, detectorType: 39, FULL_TYPE alarmWindowMillis: 3750
05-01 21:11:06.576 28754 28885 E NlpRequestHelper: failed to send request to NLP
05-01 21:11:06.577 28754 28885 E NlpRequestHelper: failed to send request to NLP
05-01 21:11:11.612 29485 29522 I SharingClientImpl: client com.google.android.gms disconnecting
05-01 21:11:11.614 28754 28916 I NearbySharing: Package com.google.android.gms has requested to unsuspend Quick Share
05-01 21:11:11.615 29485 29787 E SharingClientImpl: Unsuspend failed: null
05-01 21:11:16.653 28794 28794 D BoundBrokerSvc: onUnbind: Intent { act=com.google.android.gms.onboardingconsent.api.ConsentManagerApiService.START dat=chimera-action:/... xflg=0x4 cmp=com.google.android.gms/.chimera.GmsApiService }
05-01 21:11:16.681 28794 28794 D BoundBrokerSvc: onUnbind: Intent { act=com.google.android.gms.inappreach.service.START dat=chimera-action:/... xflg=0x4 cmp=com.google.android.gms/.chimera.GmsApiService }
05-01 21:11:16.690 28754 28754 D BoundBrokerSvc: onUnbind: Intent { act=com.google.android.gms.trustagent.BridgeApi.START dat=chimera-action:/... xflg=0x4 cmp=com.google.android.gms/.chimera.PersistentInternalApiService }