Describe the bug
If both the level and a discount code for the level have expiration dates set, the level's expiration date is applied when the discount code is used.

To Reproduce
Steps to reproduce the behavior:

1. Set an expiration date in a level's settings.
2. Create a discount code for that level and set an expiration date in the discount code settings.
3. Use the discount code at checkout for the level.
4. Observe that the level's expiration date is applied instead of the discount code's expiration date.

Expected behavior
The discount code's expiration date settings override the level's expiration date.

Isolating the problem (mark completed items with an [x]):

• I have deactivated other plugins and confirmed this bug occurs when only Paid Memberships Pro plugin is active.
• This bug happens with a default WordPress theme active, or Memberlite.
• I can reproduce this bug consistently using the steps above.

WordPress Environment
WP 6.8.2
PMPro 3.5.4
Set Expiration Dates 0.7