Magento 2.3.0 – Migrated from 1.9.3.4 – Some attributes not updating on product save

Having some weird trouble with a migrated M2 website. I’ve seen some resources on here, but they all don’t seem to be showing the same symptoms.

Migrated a site using the Magento tool – all went well apart from an odd issue with the select attributes not functioning as expected.

If I update a migrated (Say Attribute Value “A” to Value “B”), it will revert to “A” on save.

If I create a new product and do the same thing it works fine.

I’ve seen that it may be an issue in the eav_attribute table.

For reference, this is one of the troublesome attributes (which were also migrated):

*************************** 1. row ***************************    attribute_id: 586  entity_type_id: 4  attribute_code: room attribute_model: NULL   backend_model: Magento\Eav\Model\Entity\Attribute\Backend\ArrayBackend    backend_type: varchar   backend_table: NULL  frontend_model: NULL  frontend_input: multiselect  frontend_label: Room  frontend_class: NULL    source_model: Magento\Eav\Model\Entity\Attribute\Source\Table     is_required: 0 is_user_defined: 1   default_value:       is_unique: 0            note: NULL 

Compare that to a test attribute I created after migration:

*************************** 1. row ***************************    attribute_id: 1212  entity_type_id: 4  attribute_code: test_select_attribute attribute_model: NULL   backend_model: NULL    backend_type: int   backend_table: NULL  frontend_model: NULL  frontend_input: select  frontend_label: Test Select Attribute  frontend_class: NULL    source_model: Magento\Eav\Model\Entity\Attribute\Source\Table     is_required: 0 is_user_defined: 1   default_value:       is_unique: 0            note: NULL 

The only big difference being the backend_model. – I set this to NULL, but that didn’t make a difference.

Other issues I’ve noticed:

In debug.log, there’s a bunch of these errors:

main.WARNING: Attempt to load value of nonexistent EAV attribute '575'                          for entity type 'Magento\Catalog\Api\Data\CategoryInterface'. [] [] 

Also, I can’t for the life of me get these attributes to load in layered navigation. I would assume it’s related to the above issues.

Anyone out there who’s able to help at all?

Cheers