Avon high pressure floor
We have an Avon as well but we don''t see the problem you are describing. If you are relying on the little red indicator on the pump itself to tell you where you are, that might be the problem. These are just springs that can and do stick. On ours it seems pretty hard to overinflate the floor but as mentioned earlier be aware of the effect of the sun. Here in SoCal it''s a consideration on sunny days as well.
Another quick note, the second chamber of the pump moves less air with each stroke so it will take a lot of pumping to get there.