Confirm If I got the scenario right,
You got a VIP : x.x.x.x:443 for https://boe.ndc.com
VIP has its pool, within the Pool, it has its members as,
PM1 -> abc:8043
PM2 -> def:8043
You have put the entries as false for maintenance mode, and true for Operational mode.
Here I see the monitor send value is mismatching. Was it a typo error.
Your servers are having /main/system/webdev_staging/SCADA/
but your monitor query is /main/system/webdev/SCADA/
With the above monitor, I'm sure both the pool members would be marked down, ultimately your VIP is down. Making this site can't be reached.
Correct your monitor path and see if it marks the pool members as UP.
Remember, even if you put maintenance string, the pool member would be marked as UP and disabled, so existing connections on this pool members are still served till its drained.