Switch on shower/sink

We've had our MPG just over a month, and recently took it on a week-long trip from IL to NC and back. We are new trailer owners, and I'm hoping this is a simple handy-man fix we can do ourselves....

Anyone had problems with turning on the bathroom sink and pulling up the stopper switch to activate the shower head, and it not staying in shower mode? It pops right back down and the sink faucet comes on. VERY hard to take a quick shower this way.

Suggestions?

Thanks a bunch!

I have only had my MPG for a few weeks, so not a lot of shower time. I did go home and check out the operation of the switch. It seems difficult to get it to lock into place. Took a fair amount of "fidgeting" to find the happy zone, but once locked it worked fine. However, upon reading your post I have now included a small binder clip to use as a wedge..........just in case.

When you say use a binder clip, do you pull up the plug and put it between the head of the plug and the faucet? I'm willing to rig anything!