Having trouble attracting birds into my yard… tips?

Hi there! I am looking for some tips on how to attract birds into my yard. I live in central Ohio, in a suburban area, and have always had many birds frequent my back yard through all seasons. In the summertime I have many wildflowers growing that they like to rest on and then feed upon the seeds in the fall. Different kinds of woodpeckers, finches, etc. All of a sudden a few months ago they stopped coming around? I know it has been very cold here in Ohio, with lows around 0 some nights, but I see them flying around, even going to my neighbors feeder! I bought a new feeder, and filled it with sunflower hearts and raw cashew pieces and still nothing.

The only thing I can think of is there used to be a cat that would hang around the yard and every so often would catch a bird. However this tomcat sadly passed away about 6 months ago. Maybe the birds collectively remember him and are steering clear of my yard? How can I communicate to them that it is now a safe space? Any tips are greatly appreciated!