We have been troubleshooting a slow response issue for a while and think we have it narrowed down to Edge WebView2. Basically any process, like the Outlook preview pane, that uses WebView2 for rendering is causing delays and possibly occasional crashes. We are using 2019 and 2022 servers primarily with Citrix 2203 CU2, 3, 4 or 2402 with Seamless Published Applications. This doesn't seem to be an isolated incident to our environment. Are there recommendations that we can follow to improve the performance of WebView2?

not sure if this will mess with any optimizations, but for troubleshooting purproses, have you tried adding it to the CTXUVI reg key, so the citrix doesn't hook into it? Maybe look at AV logs as well

We added to the CTXUVI key on Sunday and have minimal testing with it. Will look into AV some more again. Can't really not scan it.

just for isolation at this point

Got any results yet @Steve Noel? This might be relevant to our interest. :D

In further testing with a specific example of an email thread it really doesn't appear to be Webview2, but rather the Word rendering engine. I see it performing a lot of tiny writes (512 bytes or so) in a ProcMon. There are no WebView2 process hits in the ProcMon. I see it pull the message from the OST and write out to a .TMP file in the user TEMP folder and then from there write to the AppData\Local\microsoft\windows\inetcache\Content.Word as multiple .TMP files. The Content.Word TMP files are the ones that really generate a lot of tiny writes. The busier our systems are with users, the slower this process becomes. When forwarding this particular message Outlook will go "Not Responding" while it attempts to pull the message together for forwarding. It does not have the same issue when hitting Reply or Reply All. Removing a particular Signature for the client from the message thread makes both the loading of the thread quicker and the forwarding no longer goes "Not Responding" and loads much quicker as well. The email thread is probably about 50 email exchanges long (I didn't count, just a rough guess). CTXUVI makes no difference. Disabling AV makes no difference. Moving the TMP files out of the profile container (Citrix UPM full profiles) makes things marginally quicker, but certainly is not a fix. New Outlook does not have the same issues with this same email, but doesn't have COM add-ins, so really isn't a solution I can propose at this time. @Stephan Sprathoff - What are you seeing?

Oh just a customer with worse overall performance of the Citrix Desktop since switching to Dynamics 365 that is used in Microsoft Edge and therefor creating tons of Webview2 processes. Would have been worth a shot to unhook the process if there was any performance gain from it, but guess that's not the case.