Is unbelievable that after two years it is still not solved. You simply don't listen to your customers. After unsuccessfully try Google Backup & Sync (still have many bugs), I have moved today to SOS Online Backup. It works perfectly, fast and deleted folders are correctly deleted in the cloud.
For god sake, I don't want to see all my deleted folders after months there empty. SOS Online Backup even let you configure after how many days files and folder are deleted from the cloud.