Hi,
Yes it sounds like you've customized the form for the SharePoint list (which is a Power App) - this is expected - what you'll need to do is make sure your SharePointIntegration functions treat your form correctly:

So for example in the case you described, the OnView, you would want the form to be in view mode rather than Edit/New, so you'd have it do:
ViewForm(SharePointForm1)
and make sure that all of the items you customized in the form use Parent.DisplayMode so that they use the card's view mode which is based on the Form's view mode
Then if you want to, you can hide/show certain fields on the form by making their visibility based on what mode the form is.
If that doesn't answer your question could you please provide some more info like the kinds of things you were expecting to see/not when in view mode,
Cheers,