Just as a follow up to this post, this has been happening with ALL new characters I've made since the weird issue that took place some days ago that made global friends and mail inaccessible for a time.
All characters made prior to this can use quotation marks in text chat without issue. All characters made after, this issue persists.
And Greycat is correct, surrounding it with other text via /em does post the text as intended.
This is not a big issue, obviously, just wanted to bump this.