Hi hotpink345,
Welcome to the Mattress Forum!
I’m sorry you’re not sleeping well on your new PlushBeds Botanical Bliss mattress, but a one-hour trial is of course not nearly enough for you to evaluate the product and “give it a chance”, or allow yourself to adjust to it.
The mattress you chose has a firm latex support core, with only 2" of a medium-firm (24-26 ILD) Talalay latex layer on top of that, and at only 110 lbs those components should be more than enough to provide adequate support for someone of your BMI.
Everything that you are describing points to the point-elasticity of the latex contouring to your body (in contact with your ribs and hips), and your hips sinking in a bit more than the rest of your body would be normal, as that is generally the heaviest area.
It could be that you are not used to the feel of latex, which can certainly take a few weeks for adaptation. You may also have some “learned alignment” from your old mattress which makes this product feel odd. You also may have top-of-bed products or an unsupportive foundation (you didn’t mention about either) that could be contributing to this sensation.
With all of that being said, if you truly think that this mattress is “too soft” for you, as an experiment you could flip the mattress over and sleep upon the bottom (core) side of the mattress, which would be “firmer” than the top side. If you found that to be more comfortable, it could then very well be that you do prefer a firmer surface comfort than what would normally be expected for someone of your BMI and a side sleeper.
There is some information about the many different symptoms that people may experience on a mattress and some of the most common causes behind them in post #2 here that may be helpful.
I would also suggest a phone call directly to Plushbeds if things don’t improve for you and seek their guidance. They would know more about their products and have specific suggestions for you to try. The good news is that you did choose something with a good return/exchange policy, but hopefully you won’t end up needing to take advantage of that.
I’ll be interested in learning if you adjust to your mattress or any changes that you might make.
Phoenix