u/SpottedAxis4682

I am working through Book 1 of Simandl right now and am having trouble playing in the position between 5 and 6 (E to F# on the G string). I am mainly struggling playing in the position on the A and E strings because my thumb is on the side of the neck/neck block and my fingers are having a hard time reaching to push on the string for the lower strings. Should my thumb be on the side of the neck or do I need to move it to be able to play the A and E strings comfortably?