Problems selecting / deselecting layers in latest version of photoshop

Hi - has anyone had any problems when upgrading photoshop with selecting layers?
With the latest version I’m having problems with layers - using control d to deselect a layer / selecting several layers with the marquee tool (it only selects 2 layers) / it’s very quick to go from layer selection to the rotate tool, so then I have to deselect the layer and select again.
With my old version of photoshop, I could manipulate layers very easily - selecting using the marquee, deselecting using control d - but something has changed with the installation of the latest version. Any ideas? It’s driving me insane.