MacOS 10.15 Catalina require a 2048bit certificate encryption.
In the last message of Emily for ATP 200 :
Have you a BETA test firmware for Zyxel ATP 500 ?
The firmware for ATP 500 is sent to you in private message.
I test the BETA firmware V4.35(ABFU.1)ITS-WK46-r90773 since 24h, it's work with MacOSX Catalina 10.15 (2048 bits encryption), but it's very slow.
The CPU used it's at more than 90% with only 20/30 users and 600 sessions.
Is optimization possible ? Wait and see
I can imagine that device issue/validate a certificate with RSA key 2048 bits would be slower than before base on same hardware platform.
Maybe you can add well-knows https site into device exclude list. i believe that it would be helpful regarding to your case.
BTW, If you type CLI "show cpu average", which one caused the high CPU usage?
Yes, i have in SSL Inspection whitelist the confiances websites with the most connections like Windows Update, office365 ...
For the moment, i disable SSL Inspections for Catalina Mac IP.
me too problem with ATP200.
I currently use mac osx 10.14 (Mojave)
A solution is needed.
MAC os 10.14 should not have issue. the limitation is on MAC OS 10.15.
Here is the Apple announcement;