PO number in userform does not want to change to next po number

[Nicholas1978]

Hi,
Hope that all of you are doing well. I created a userform, where it looks up the specific item number and pull all the details into the userform, where there stands for example three is found then you can view all the item number transactions with a right or left arrow button. The problem is the following, it just pull in the one item code, when i enter the next code, it does not want to change, it just stays at the one code.
Can any one help me in this matter or show me a better way of doing this? Please find attached the file as well for an example.
Thanks alot.

[StevenM]

See: Nicholas1978_LoopUnion.xlsm