The first thing I notice is that you are two bug-fix updates behind. You should be running 11.0.4. Now, I'm not sure it's related, but it (probably) couldn't hurt to get up to date.
I took your advice & upgraded - now running 18.104.22.168
Crossed fingers and tried opacity again.
Thanks for the suggestion anyway — like you say it was worth a shot.
If any one else has any recommendations, or workarounds i'd be very glad of them.
Your blending mode is set to Color. Us Normal instead.
Well noticed and thanks for the advice.
Unfortuantely I changed that whilst I was trying to find a fix (I should have set it back to normal for the screenshots to avoid confusion).
This issue occurs using normal blending mode too.
Thanks for the suggestion anyway.
Yeah, just checked. Seems to be an oddity with this particular layer style...
Thanks for checking!
Is there a reason you're using a layer style instead of the Generate>Stroke effect?
I have tried to use generate > stroke but it appeared that using it I could not...
- set the stroke to be inside the mask
- avoid some anti-aliasing as the stroke is 3px aligned to the center of the mask, rather than pixel perfect.
basically I could not achieve a sharp 3px border inside the image using it.