After updating to Org 9.6 this match in the agenda
'SCHEDULED<"<+2d>"+SCHEDULED<>"' shows all scheduled items event if they
are far more in the future than 2 days.

Tracked this down to a commit (e022a0cea11a0e784ba20ac478a033da7fb1bb7f)
that changed the regular expression to recognize timestamps:

-    (timep (string-match-p "^\"[[<].*[]>]\"$" pv))
> +    (timep (string-match-p "^\"[[<][0-9]+.*[]>]\"$" pv))
>

If I understand it correctly, this new regular expression only matches
strings that start with < and a number. So strings like <today>,
<tomorrow>, <+2d> and so on are not working anymore.

If I change the expression to the one before and evaluate the function, the
match works again.

A big thank you to all the developers behind org-mode!

Best wishes.
Daniel Hubmann

Emacs  : GNU Emacs 29.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version
3.24.20, cairo version 1.16.0)
 of 2022-07-18
Package: Org mode version 9.6 (9.6-gd500b4 @
/home/hubisan/.emacs.default/straight/build/org/)