Yes, we’ve found this necessary on several upgrades, though I don’t recall exactly which versions. It’s now the first thing I check if an OPC UA connection isn’t working after upgrade.
The only other OPC UA issue we’ve had on upgrade is from v7.9.12 to 7.9.13. We had to enable security (and accept the certificates from Ignition) on a couple older OPC UA servers from another vendor to avoid an error stating nonce must be greater than 32 kB. They were working with no security on previous versions. Newer OPC UA servers from the same vendor did not produce this error.