Galleries: Live site showing < before a gallery block

[ahmadbaig1]

Quick summary

Tiled gallery is showing less than "<" sign before the gallery begins.

I thought we could remove this from the code editor, but apparently, this sign is not showing up there.

This is happening on various themes, both on FSE and classic themes.

Steps to reproduce

1. Create a page on a simple site.
2. Add a tiled gallery.
3. Check the Live Site.

What you expected to happen

I did not expect the "<" sign before the gallery.

What actually happened

The "<" sign shows up just before the Tiled gallery.

Browser

Google Chrome/Chromium, Mozilla Firefox, iOS Safari

Context

User contacted us at zen-5500682 and I also tested it on my test site, multiple themes, simple as well as atomic site.

Platform (Simple, Atomic, or both?)

Simple

Other notes

Only happening on Simple sites, not on atomic.

< sign not showing up on the code editor.

I upgraded my testing site from simple to AT, and the sign disappeared.

Reproducibility

Consistent

Severity

Most (> 50%)

Available workarounds?

No response

Workaround details

Not sure.

[ahmadbaig1]

Issue reported here as well- https://github.com/Automattic/wp-calypso/issues/66865 But not sure if that is for all galleries or only Tiled gallery. Reported here as well- https://github.com/Automattic/wp-calypso/issues/66876

[carinapilar]

This one seems to be the first report: https://github.com/Automattic/wp-calypso/issues/66865 - maybe we can close this in favor of that one?

[oskosk]

Closing as duplicate of #66865

Fixed in https://github.com/Automattic/jetpack/pull/25795