Wrong date format on lastmod in series-group

[LuigiRnd]

Expected Behavior

On my website, when generating the sitemap.xml by the plugin I'm using (AIOSEO), the date for the 'lastmod' entry in 'series_group-sitemap.xml' is in the format '-yyy-mm-ddThh:mm:ss+hh:mm' instead of a 'yyyy-mm-ddThh:mm:ss:+hh:mm' format

Current Behavior

Possible Solution

Steps to Reproduce (for bugs)

download the sitemap from the link below and check line 32

1. https://informaticando.eu/sitemap.xml

Context

Your Environment

I use a free version of PublishSeries v. 2.11.4
Wordpress v. 6.6.1
All-In-One SEO pro v. 4.6.9

• Version used:
• Browser Name and version:
• Operating System and version (desktop or mobile):
• Link to your project:
  sitemap.xml.txt