I have the HWH hydraulic slides, Living Room and Bedroom and the BR slide did the same thing to me.
Brought it into Winnebago factory service just a couple days ago and they changed out 2 hydraulic solenoids to fix that problem, telling me that's what was needed to fix it. I'd heard the same thing from others here on the forum...that 2 solenoids had to be replaced.
Cost was $172 each for the solenoids and 1.7 hours labor for $221. So total of $565.
The Winnebago P/N 131306-12-702 just in case you need it. The manufacturer of your slide system would have there own P/N I'm sure and it would likely be different.