Module development and code questions

Probably a stupid question but as I have a lot of rather structural changes on development , just migrated my dev environments to use  ddev and took this somewhat older  project over from another developer I am suddenly afraid to mess things up and get rattled by conflicts in the config yamls or idiosyncratic composer messages.....

The project has a simple branch setup

2 branches
a main branch which is used as the release branch so which is usually live on the server
a develop branch which is a lot of commits ahead of the main branch

Hi there. I've been working on a Drupal 10 custom module -- a block, specifically -- and it was working great. But it occurred to me I could use another column in the table, so I added one through my DB client.

Now, here's the PHP code that's causing me trouble:

I've created a contact form module which allows me to add my custom contact form using the page layout builder.

The site is hosted on Pantheon, and they recommend using the sendgrid_integration module. 

When the form is submitted, sendgrid reports that the subject is empty. Why would my data not be getting through to the sendgrid_integration module? 

I started using the Simplenews module of the latest version: 4.1
The site is on Drupal version: 10.4.6.
Sending newsletters works fine. But you need to press a button!

The problem is that I need to:
1. PROGRAMMATICALY add new issues (types: NewsLetter issue);
2. PROGRAMMATICALY activate them for sending.

I can't find a description of how to do this. For some reason, the API description of this module is unavailable: http://api.worldempire.ch/api/simplenews

Help! This is probably a pretty simple answer for some of you all.

I'm trying to display my full body content of text.

<!--break--> no longer works. 

I've created a custom module to implement multi factor authentication(MFA). I have a "settings" page. It's implemented with  mfa.links.menu.yml, mfa.routing.yml, and MFASettingsForm.php files in the standard way. I have another module that has a settings form also implemented the same way that works fine.  When I save the settings form I get an unstyled page containing just the text "Contact Support" and the data is not saved. The Apache access log records a 200 for the favicon.ico and thats it. Nothing is written to the Apache error log.