How to downgrade an app on a brand new iPad?

Help. I am a senior caring for my very senior parent. She plays puzzle and solitaire games all day long. Loves them. Since the last update, the puzzle sizes became smaller and we can no longer change them. It continues to open on an incomplete puzzle that we cannot move away feom, notpr can we select other puzzles. I have tried to contact the develper, to no avail. The older app works on her older ipad. Is there no way to downgrade the upgraded app on her brand new ipad? Thx.

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Original Title: Downgrade an app