Add pool member state diable using bigpipe command v9.3.1

b pool test { monitor all tcp } -> work 
b pool test member 10.10.10.10:80 add -> work 
b pool test member 10.10.10.10:80 { session disable } -> work 
b pool test member 10.10.10.11:80 { session disable } add -> work

I would expect those commands to work in the bigpipe shell on v9.3.1, but I would verify that your pool has two members when you're finished. I suspect (but may not be correct, it's been a really long time) that you'll only have the 10.10.10.11:80 pool member.