i have some page-items that can contain user-saved "notes". If Page-1 sends the string to Page-2, and it contains special chars like comma, colon etc.. it breaks.
I understand why it breaks.. apex is sending these over a querystring.
what's confusing me is why the apex framework didn't auto-escape the comma/color chars automatically? it escaped other special chars in the string that the rich-text-editor page-item generated for html chars.
turns out the fix is described in: https://www.foxinfotech.in/2019/10/oracle-apex-escape-special-characters-when-passing-parameters-to-other-page.html
ie, i had to wrap my page-item substitution string with back slashes \&PAGEITEM.\