I had a Walther PPK (S&W days) that only had half the barrel rifled, but it still hit the target board at 7 yards, it was all over the target board but it still hit it.
I had a Walther PPK (S&W days) that only had half the barrel rifled, but it still hit the target board at 7 yards, it was all over the target board but it still hit it.
You only changed the front sight. Sounds like a mismatched front to rear height issue. Are you sure the front sight packaging said it's for a G26? Maybe sent you the wrong one.
Probably can see it with an image taken from the side showing the height. Compare the front sight heightwith the one you removed. Measure with a caliper.