Maintenance page iRule

It's a little hard to read your irule, are you able to copy the text rather than a screen shot?

I would try to define exactly the pool you want to check, rather than relay on [LB::server pool] and specify the number of active members being less than one, as being the condition in the 'if' statement.

[active_members my_pool] < 1

Can you give an example of the URI requests that aren't working based on your code