After pulling out my non-existant hair, I decided to decompile the Sitecore.Forms.Core.dll. Lowe and behold, there is a check in FormsHandler.cs if the site is in DisplayMode.Normal to ignore all save actions.

In our particular case, the entire site is hidden behind the Sitecore login, therefore to test, it is our common practice to login to Sitecore, then preview the site. Previewing the site sets this flag to DisplayMode.Preview, thus causing all save actions to be ignored.

Appending sc_mode=normal to the query string properly sets the flag to DisplayMode.Normal and allows all save actions to execute.

I found no other posts about this anywhere, hopefully this helps someone some day.

After pulling out my non-existant hair, I decided to decompile the Sitecore.Forms.Core.dll. Lowe and behold, there is a check in FormsHandler.cs if the site is not in DisplayMode.Normal to ignore all save actions.

In our particular case, the entire site is hidden behind the Sitecore login, therefore to test, it is our common practice to login to Sitecore, then preview the site. Previewing the site sets this flag to DisplayMode.Preview, thus causing all save actions to be ignored.

Appending sc_mode=normal to the query string properly sets the flag to DisplayMode.Normal and allows all save actions to execute.

I found no other posts about this anywhere, hopefully this helps someone some day.