Memberships not recorded since mid April 2018 (using Webform)
ok let’s figure this out:


add the webform_civicrm module version + civicrm version to your question
check if there are any drupal database updates to be executed
use (install if you don’t have it yet) node_clone module to clone your webform
on the cloned form: remove the multi-value fileds - check if the form works without them
use (install if you don’t have it yet) https://civicrm.org/extensions/civicrm-log-viewer to view any configandlog file entries; 


Let us know what clues you can dig up.