Can you show a screenshot of the split transaction details?
The first thing I'd try here is to delete the transaction completely and then re-enter it. The report seems to be "seeing" something that isn't there.
What version of Quicken are you running? Please go to Help > About Quicken and let us know what it says there. I am running R48.9.
What built-in report is this based on, and what customization options have you selected? It is not Itemized Tags, because that does not have a Subtotal by option.
The Banking Transaction report does have a Subtotal by option, which appears to match the screenshot you show. In that report if I select just one of the Tags in the split, the split is handled properly.
"This is a custom generated report, not based on any built-in report."
No, ALL reports in Quicken are based on the built-in reports. You've taken what looks to be the Itemized Payee report, customized it, and saved it. If deleting the transaction and re-entering it doesn't work, then, Quicken has been known to screw up Saved Reports created under previous versions so perhaps the next thing to try is creating that report again under the current version.
@DaisyDoo I have seen some posts on this site about tags getting 'combined' in reports and presentations when they should not have been. I think Quicken has acknowledged the problem, but I did not search out any of the relevant posts. This issue seems to come from split transactions that used different tags for different lines which fits your ase.
I think still with what you have, you may be able to get to the right report with a tweak to your report customization.
Customize the report, Tags tab, in the Tags Contain field enter ~94_Del-Sol. That lead character is the tilde ~ a squiggly hyphen that is telling Quicken to NOT include transactions with tags that include that '94_Del-Sol' string.
Hope this helps
A relevant discussion?