ToBackendKey instance not generated for custom key

I'm migrating from 2.8.2 to 2.13.2.1 and found that I can't use fromSqKey and toSqlKey any more, the compiler complaining that there is no ToBackendKey SqlBackend instance for the record I am using. I'm only migrating so the code works perfectly with 2.8.2.
I found out that some of my records have the ToBackendKey instance defined but some don't. I realized that all the record which I override the sql name don`t work anymore.

For example

StockAdjustment sql=fames_stock_adjustment
    Id sql=stock_adj_id
    comment Text
    date UTCTime
    status PendingStatus
    user UserId 

(note Id sql=stock_adj_it) There is no ToBackendKey SqlBackend StockAdjustment instance.
Is there a workaround ? I tried addiny SqlBackendKey as a type but it doesn't solve it.

Reproduce the migration using the supplied StockAdjustment declaration and the fromSqKey/toSqlKey calls, then inspect how the ToBackendKey SqlBackend instance is generated when a custom SQL name is used. Done means the instance is generated for this declaration and the existing conversions compile under the newer version.