The Update Ivy panel on the bottom left is vanishing when I switch to another object. Any option to bring it back?
I know this is an old question, but I'm gonna resurrect it.
Yes. What you're looking for is "Adjust Last Operation...", which can be found in the Edit menu. The windows shortcut for it is F9. This will bring back the parameter adjustment for the last operation you did.
Bear in mind this is just getting the LAST operation, so if you've done a couple of other things since, then the Ivy is not going to be the last operation and so it won't work.