Solar panel use

I have a solar panel fitted to my van by Marquis. It should charge both lesuire and van battery, I paid extra for this option. Went to use the van this week and the lesuire battery is completely flat. For the Lesuire battery to charge do I have to leave the master switch on? Marquis are closed until the 3rd Jan so I can't check with them but I'm sure they didn't mention it to me last March when they fitted the panel. Lesuire battery was new in Feb this year. No issues until this week. Thanks for any help.