The backup config file in V5.2.0-5.2.4/V5.3.0-V5.3.1, which contains certificate config may not be restored properly (causing config lost). After upgrading to V5.3.2, please discard the old V5.2.x/V5.3.x config file, then backup the config file in V5.3.2 again. This should solve the problem.
Keep the old SSL version predefined config to allow the upgrade to continue smoothly.
HSM doesn't support TLVv1.3. If the HSM certificate is used in VS, the TLSv1.3 handshake will fail.
Workaround: Please uncheck the TLSv1.3 in the SSL profile if you are using the HSM certificate to avoid potential handshake failure.
To upgrade image for VM platfroms, because of the boot partition size limit before 5.1.x, please be sure to upgrade to 5.1.x image first to adjust boot partition size, then upgrade to 5.2.x and 5.3.x, or else it will report "Unmatched partition size" error when upgrading.
No such issue for physical platforms.