+1 to that. You could also, as LRod suggested, get a more "aggressive" razor. One example that might work for you is the Razorock aluminum Lupo.
But I found I don’t lather good, I don’t know if it’s my brush or the soap.If you don't feel any stubble, it might be just because of your skin and whisker colors. Some people have a shadow even if they shave perfectly close.
Congratulations on getting to the point of not feeling stubble! That's a big step. Keep on working on your technique. It is a fun, but sometimes frustrating, hobby.
Try adding more water as the lather may be too dry and looks dull in that instance. The soap is capable of producing a good lather. Most instances where the lather disappears on the last pass is when not enough soap is loaded. Generally load more soap and if you find you have a lot left over then reduce your brush loading time.But I found I don’t lather good, I don’t know if it’s my brush or the soap.
If you rub your finger against the grain and it feels smooth you can do no more. It looks much better than before.
I still think you may be shaving too steep and the handle should be angled further away from your face for better results. For comparison, shave with a cartridge razor to see if you are improving.
That's a LOT better than the last picture you posted. Congratulations on the improvement!
My advice to you is to just keep practicing and tuning your technique with the equipment you have. Don't do what I did, which was to switch a lot of things. That DE89 is a great razor, use it for a couple months and keep working on the technique. Then later you can start switching blades or other variables. If you have coarse hair like me, you may want to try a sharper blade.
Oh, sorry, I thought you had a DE89, the Merkur 23C is also a great razor. Stick with that and your Astras and focus on your technique for a while.
Only after you make more progress should you start switching things out. I have heard the Merkur are not very sharp, but haven't used them myself. When you get to that point and want to try a sharper blade, I would recommend trying a Nacet or a Perma-sharp blade. They aren't as sharp as a Feather on the first shave, but are more consistent.
I checked, my face is still smooth after I shaved this morning, but not as smooth though since it’s been 13 hours since I last shaved
The blade gap on the 23C is ~ 0.7mm and has positive blade exposure which is fine for daily shavers. You are probably shaving at a steep blade angle which is pulling the blade edge too far from the skin. Draw that handle further away from the face to get a less steep blade angle....but I find my Merkur 23C doesn’t have much gap between the blade and the block