@tomjohn77 If that suggestion doesn't work just reorder the manually edited es_systems.cfg so that the the system you want to start on is at the top and the system you want to be left of the starting system is on the right then put the Retropie menu "system" in the middle of es_systems.cfg
Please do not post a support request without first reading and following the advice in https://retropie.org.uk/forum/topic/3/read-this-first