I run Moodle 3.6.4+ (Build: 20190524) with postgres and got a problem with recycle bin:
When I delete an activity or material in the course, it appears in the recycle bin after the cronjob. There I can click on restore, but nothing happens. The entry disappears from the recycle bin, but is nowhere to be found. I tracked it with a 'label' in the database. The 'label' ends up correctly in the table "mdl_tool_recyclebin_course". After the restore the entry is completely lost.