Cas14/15 is about normal for most ddr4 2133, so Cas16 is a little high, especially when it's possible to get 10-10-10-20 (1T) out of some sticks at 2133. But it's not unheard of for lower grade models to run more relaxed timings
You could probably get away with manually setting 14-14-14-32 (1T), but I'd not push those sticks lower.
Run memtest64 overnight after any changes.