Finally I am seeing people having similar issues with PS 2020 and hoping to make some noise and get Adobe to address this bug eventually.
Every time I close and reopen PS, on my WIN PC or WIN laptop, it resets the panels to it's default values. It all started with the layers panel, shuffing all my custom, neatly organized layer styles into one folder calling it 'Your Styles', resets the panel settings and adds the default layer styles.
The same goes for the Brushes and Swatches Panel now, only started a day or two ago. But these two panels get completly wiped out, removing all my custom assets and leaving me with the default assets and resetted panel settings.
I have done so much troubleshooting which did not make one bit of a difference, even uninstalled the whole CC suit and starting from scratch.
Adobe community thread: https://adobe.ly/2vhbIzK
Many, many more people reporting this issue!
Thanks.
Janine