SWT staff are getting worse and worse I'm afraid - whilst the vast majority remain very pleasant if sometimes rather clueless, there do seem to be an increasing number of "tools" around.
For example in the last couple of months I've been challenged/given hassle for break of journey at Basingstoke and Winchester three or four times when returning from Reading/London on Day Returns. Its flipping basic that BoJ is allowed on outward and return journeys on these SWT tickets.
Away from the topic being discussed, I have to agree, based on my own anecdotal evidence, that gateline staff at SWT managed stations do sometimes appear clueless when it comes to BoJ rules.
I've been refused exit at Salisbury, where I was changing trains, with a ticket valid for BoJ, by a gateline staffer. On querying this made up rule I was told I could face a Penalty Fare! I had to wait nearly 10 minutes for a station supervisor to turn up and confirm I was allowed to pop outside for a smoke! At Woking I had a gateline staffer say to me, "You can't exit here, you've got a ticket to London." Again, when I had a ticket valid for BoJ.