Presumably, from your description, the changed appearance of which you complain is the new Liquid Glass presentation. While Liquid Glass cannot be fully disabled, there are some key settings that ameliorate the most intrusive elements.
iOS/iPadOS 26.1 introduced a new setting that subtly charges the appearance of Liquid Glass:
Settings > Display & Brightness > Liquid Glass - select Clear or Tinted
Sadly, for iPad, this new setting makes very little difference for those that struggle with both the appearance and overlapping screen elements introduced with Liquid Glass. If you are experiencing difficulty with the new Liquid Glass UI, there are other settings that can significantly improve the appearance and suppress the majority of unwanted effects:
- Settings > Accessibility > [Vision] Display & Text Size > Reduce Transparency - set to ON
- Settings > Accessibility > [Vision] Display & Text Size > Increase Contrast - set to ON
- Settings > Accessibility > [Motion] Reduce Motion - set to ON
Each if these settings can be used individually, or in combination. Setting Reduce Transparency alone (1) will likely suppress the majority of your issues. The Reduce Motion setting (3), if used, will eliminate the "lensing" effects of the Liquid Glass UI. Experiment; you should find a combination that works for you.
I suggest that you begin with setting Reduce Transparency to ON - and then, if needed, experiment with additional use of one or more of the other options.
NB: The new Display & Brightness > Liquid Glass setting can only be changed/toggled while Reduce Transparency is set to OFF. You might find that setting Liquid Glass to Clear, prior to enabling Reduced Transparency to ON, may give the best result.