Hai!
I'm not 100% sure what you're trying to do - but I think it's that you're seeing an older version of the connector, and you want the snazzy new version with a larger Cypher entry box.
Power BI is a tricky beast to find the custom connectors location - if you can I would search your disk for neo4j.mez which is the connector file, and that will show you where it is.
Normally, it's something like C:\<User>\Documents\Power BI\Custom Connectors - but if your User folder is elsewhere, it's entirely possible that this is in a different place. I would delete any .mez file you find, restart Power BI, and check that 'get data' doesn't show neo4j as an option.
Then copy a newly downloaded version back into the place you deleted it from.
I personally had a point where I had 3 copies of the .mez file on my disk and was replacing the wrong one for ages 
All the best
Chris