#161 is only 10 minutes apart from #957.
#163 is only 30 minutes from #959.
#159 is ok on the outbound leg, but the return flight leaves at the exact same time as #956.
You need to make sure flights are 1 hour apart on those smaller routes. You're losing all those pax because you have flights too close together. High prices might also be a problem, but can't tell if you actually have them high.
Fix the timings, and those routes should be fine.
You're doing that quite a bit, not just on LH planes. #547 & #937 are EMBs 30 minutes apart on a 280 pax route. #487 & #1263 are only 5 minutes apart, #371 is a fill-in on your 767 that is also very close to both of those.
Rest of your airline looks ok, you're going to end BW with 250+ planes, multi-billion CV, even with those scheduling issues. Buying some of those planes instead of leasing everything and I assume now sitting on ~2 billion in cash would also have helped.
So basically, you've got most of the basics working, you need to pay a bit more attention to scheduling, not putting flights close together. You should also learn how to 7-day schedule, as it makes it much easier to avoid badly timed LH flights, helps your efficiency. And your current airline has quite a lot of longhaul, more than enough to be using it. Since you've got so much cash, and BW is mostly for learning, I'd actually suggest cancelling all of your LH routes, and then rebuilding all of them from scratch on good 7 day schedules.