One of the massive problems for ticket office staff, is that most Station Managers aren’t retail trained, so if you asked them to sell a ticket they can’t! So, if there as a training issue, how do you address it?
As a member of ticket office staff myself, I feel this is an excellent point.
I recently asked colleagues on social media about a ticket issue I felt that onboard staff had got rather wrong. Whilst the vast majority of colleagues agreed with my point of view and equally couldn't understand why the staff had been so heavy handed, the odd one or two colleagues thought I was purely wanting to slag off fellow colleagues, because I could have simply asked my line manager for advice. But knowing that my line manager isn't ticket/revenue trained, I didn't think there was much point in doing so.
Also from personal experience of working with colleagues- many often don't have much knowledge of the UK Rail network compared with myself. Which is unsurprising seeing I'm a rail enthusiast, hence my presence on this website. Others have good intentions but are wrong. e.g. Someone I know refuses to offer split tickets where the journey involves a change of train incase the customer misses the connection. (despite me reiterating several times it's irrelevant)
Also from personal experience the tickets I occasionally struggle with are usually unusual ones which we don't sell much. e.g. Rail and sail.
Sadly before I got my job on the Railway, I experienced bad customer service at nearby ticket offices, with staff refusing to sell me Advance First singles which were perfectly valid (and I could see them online) just because you had to specify a different route which was much slower. So I fully understand why some members may be sceptical about using Ticket Offices.
The flipside to this, is that I sometimes have customers asking me to sell them a cheap split ticket they've been offered online- but the website doesn't expand to tell you what the combination of tickets is, so it would literally be a guessing game trying to work it out, whereas the customer sees my inability to suss it out as me being incompetent.