I'm kind of the opposite, got more free time than I've ever had , done 30+ years as a volunteer on the NYMR and at the point of telling them to stick it. I'm bored stupid when I'm there, transferring to something else on the railway is nigh on impossible and I am getting to the point I don't have the patience to deal with the people whose only qualification is to stick a huge hat on with gold braid and think they're gods gift to railways.
I would look at the turnover of volunteers, if the only people there have been there forever and there are no new faces walk away. If there's a really good mix and people can be bothered to take time to talk to a new/prospective volunteer that's the place to go.
I took a few months off from the Moors for medical reasons and did my first guards turn in ages in April and I saw 2 different attitudes on display, the most prevalent was "you're new so I'm going to ignore you or use my greater experience to try and bully you". The better one was the one person who came up and said "Hi, I've not seen you before my name is ******* if you have any questions I'm happy to answer them".
To me you need to get something from your volunteering hobby, a sense of achievement or that you've turned up had some fun with like minded people and that you've helped the railway in some manner. If you don't get that vote with your feet!