It's been about a month and photoshop is always lagging when I switch between tabs (takes like 2-3 seconds). And this happens even with new empty documents. I've tried completely uninstalling and reinstalling PS, but nothing worked
Ahmed: How much memory is installed in your machine, what kind of machine is it? Have you ruled out malware (by using a legit antimalware program and not one of the freebies like Avast) How about storage space?
First go to help in your Photoshop App and select Systeminfo. Copy and Past it here. Then everyone can see what specs your System has. I Could be, that your Graphics card can't handle too much open pictures. And if you don't have an SSD loading times take time like you mentioned (2-3Sec.) for each switch or is your data not local and on a network. For me Photoshop switches fast. Or does it also happen with just small picture and colors like my video. Im on a MacPro2019 and a Vega II duo GPU. https://shared-assets.adobe.com/link/c07b8836-a1fc-4cbe-6e82-955e15a5dbb1