We will be arriving at Montreux 11 AM. We will have 5 large suitcases with us and would like to know if there is an option to store the bags anywhere for 3-4 hours. Rick Steves’ guide says there are limited number of lockers on the station, is there a “manned” left luggage facility at the station?
According to the website for the Montreux train station, they have 24 large lockers for 9 CHF each. The size is 44.7 x 61.5 x 88.0. You will need coins for payment.
https://www.sbb.ch/en/station-services/at-the-station/railway-stations/montreux-station.html
As far as I can see, that is your only option for the suitcases.
There are lockers (color blue) on the platform where you get on or off the train; there is no manned left luggage.
And to echo you need coins. If you don't have coins there is a convenience store outside of the station
When I went through that station it was undergoing a lot of construction and there wasn't much open, but that was a few years ago. You might reach out to the station directly by email or phone to confirm, or the TI.