It's great that you made it work with Aria DB engine, I think that UNA wasn't working with InnoDB in your case, because you had incorrect setting for transaction_isolation option, which you said you wasn't able to specify. I think for MariaDB this setting should be named tx_isolation instead of transaction_isolation
Finally!!!!! Somehow I always end up fixing it my own way. So changing to Aria has resolved the issue. There has to be an INNODB option that cause an issue but not sure at this time. Everything was the same though. At the time I will stick with Aria. Keep in mind trying Alex's fix for #INNODB for #MySQL did not work on #MariaDB for me. I would advise at this point unless tested and a resolution, do not use INNODB, but use #MyISAM or #Aria engines instead if you use MariaDB. If you have a fix please share.