Set mower on a box under the front, or rear.Where the wheel won't stay in adjustment. Try to turn the wheel around until the handle clears the notches on the adjuster. Then bend the handle in toward the mower deck. it is springy but can be bent in some. Then try the setting of the handle in the notches. It should be better.

We have both an electric and a gas mower. I think the electric is great for the flat areas PLUS because it's quiet, I can run it before the neighborhood's 10 a.m. weekend no-mowing convention (it's not a "law" but we do talk about those early risers) or later in the evening (after I hear we're in for a storm overnight or the next day). An electric is too much work for our whole yard because the lawn slopes too much. Downhill is just fine but our gas mower is self-propelling and gets back uphill without too much extra work from me. I would guess that in Florida, your grass grows like crazy all the time. Maybe you could just count your mowing as your main exercise and do 20 minutes every day with an electric mower. The gas mower needs more maintenance than the electric, and the gas does smellwhich might be even stronger in your weather. If you do get a gas machine, and start smelling it inside the house, don't hesitate to replace the gasket around the door That said, with the better and better (longer lasting and stronger) batteries available every year, we're in for a battery (no-cord) electric if/when ours bites the dust. Hey! since you're no longer paying a service, you might look into buying one of those lawn mowing robots. I've seen them--they are like that vac'ing robot you can find on youtube riding cats around the house. I can just see one zipping around, covered with little lizards going for a joy ride!

They are reasonably good for that price range.

Died grass build up in the drive pulley or possibly near the transmission creating a little more tension than normal? You could look on a parts list and see if maybe there is a missing belt guide as well.