I have tried on numerous occasions to resolve what I feel is software related problems /glitches on QB online, after several lengthy and I mean hours of talking to India and having people search the internet for the answer, instead of knowing the answer, I tried to get a higher-level technician and was told over and over again to file a help online which I had done twice before and was redirected to overseas ....again... I think the problem really needs to be addressed even if we can't resolve it, others must be having the same issue. my invoices do not print correctly and are subtotaling even when the subtotal is not selected, seems to possibly be a linked issue with Tsheets, but not sure, worked for hours with other techs and can't figure it out ... need a real human who ACTUALLY KNOWS THE PRODUCT, not someone who is surfing the web looking for answers, I've done that already.
Let me please just put my five cents. I am using QuickBooks Online for more than a year and a half for now and there were no issues with subtotalling without me wants it. So, I believe it might be that the software you have mentioned in your post indeed has some impact on this matter.
You can also try using some third-party apps to have your invoices created in a fast and reliable method. You can find some such apps on Intuit App Store. I personally am fond of using Business Importer app. Any large csv or excel files will be correctly reflected in your QuickBooks - very convenient.