3D Printing Layer strength on swept fincans

I found out that I'm having a layer-layer strength problem with my printed fin cans.

These are scale fins, and swept back. The weakness/brittleness is all aft of the body tube. I print them leading edge down, so that's above the can/body as printed. No issues in the 'body' portion.

I'm printing at 2-3 shells and 40%. PETG. 250C. 45-50mm/s. Retraction - but 'retract at layer change' didn't make a difference.

I'm thinking about printing them solid. Or slowing down at that height to have more time on each layer. Or both.

Any other ideas?

How thick are the fins? I usually print the small ones (less than ~1/8th inch thick) solid and larger ones with very high infill and 3 to 4 perimeters. The only other thing that comes to mind is trying to dry the PETG in case it has absorbed some moisture.

3 and 5mm. I’ll be reprinting the thicker ones. The thinner only had one problem spot, so I’m repairing.

I keep my filament in Rubbermaid cereal containers with desiccant in the bottom - it’s still blue. I have unfortunate experience with damp filament.