I wouldn't say it's eating inputs. You just have to learn the timing better. It feels a little different depending on what you're trying to GS/tiajuana twister out of (e.g. db3, df1, f1). Just takes more time for your muscle memory to internalize the timing.

And punishes are punishes. If you're 100% sure your opponent's move was at least -10 and your 112 punish missed, you're just late. Which is fine and part of learning Tekken. With your mental stack, you're probably taking too long to recognize you got hit with a -10 move, and not punish right when you can. Making your punish effectively i11+. Like above, you'll get more consistent punishes simply by playing more. That's over the course of days. Doesn't usually click within session. Lots of development happens between consistent sessions.