What version of Magisk are you using? i use the latest canary magisk, using edexposed v0.4.5.5 CTS true
see this page https://xdaforums.com/pixel-4-xl/how-to/xposed-discussion-thread-t3992607
I use the latest canary magisk too.
Pixel 4XL 1st StockROM(Oct patch) is v0.4.5.5(CTS ture) & GB works fine.
Nov Patch is v0.4.5.5(CTS false), v0.4.6.0(CTS ture) & GB with waiting for framework to respond.