Migration of QBMac to QBO

I signed up for QBO 6 days ago. I've been using QBMac for 20 some odd years. I'm switching so that my business can set up a POS system that would integrate with QBO. I first migrated data directly from QBMac to QBO. Took 24 hours but it's a 1.7GB data set so not surprising. At first glance most everything looked good. Then I saw the inventory asset was off by hundreds of thousands of dollars. Then I saw that all the items had been converted to Non-Inventory Items - most are Inventory items (over 10,000 of them) along with a few non-inventory items. After contacting migration support and receiving little help, and agent noticed a statement, buried deep in a help article that this is what happens when QBMac files are exported to QBO files. In order for migration to keep Inventory Items as Inventory Items a backup to a .qbb file has to be created and that file uploaded to be converted to QBO. So I created a .qbb file and tried to upload it. First problem is that the upload portal would not work. It either ran for hours with no end result (it should take about 30 minutes to upload the file) or I would receive a failure message. A migration agent suggested we try an assisted migration. Initially that upload portal wouldn't work either, but after a day of trying the file was finally uploaded. I specifically mentioned as part of the assisted migration process that I needed all inventory items to be uploaded as inventory items. After waiting all weekend I received notice today that the migration had been completed. Logged into QBO, immediately went to look at Products/Services. Once again all Inventory Items had been uploaded as Non-Inventory Items. I am at wits end. Does anybody in this community have any experience successfully migrating a QBMac file with inventory to QBO and successfully getting Inventory Items exported as Inventory Items? HOW DID YOU DO IT? Thanks.