… in a course/membership
fix #777

Description

See:
#777 (comment)

How has this been tested?

Manually, adding new plans, modifying and saving existing ones, reordering them:

• with the Classic Editor plugin (so the old wp editor).
• with the block editor and a Classic Editor block
• with the block editor and the course page built with the Elementor editor (which basically is equal to say see the previous bullet)
• with the block editor e no Classic Editor block

Types of changes

Bug fix (non-breaking change which fixes an issue)

Checklist:

• My code has been tested.
• My code passes all existing automated tests.
• My code follows the LifterLMS Coding Standards.