I was working on something unrelated, but I hit this same error, detailed the issue in Jira, and have proposed a workaround.
The issue is that there is a feature in Hive called the REGEX Column Specification. IMHO this feature was ill conceived and is not standard SQL. It should be removed from Hive and this issue is yet another reason why. That's what I was working on when I hit this issue.
When Hive looks at the table name surrounded by back ticks, it looks at that string and determines that it is a Regex. When Hive looks at the table name surrounded by quotes, it looks at that string and determines that it is a Table Name. The basic rule it uses is "most anything ASCII surrounded by back ticks is a Regex."
However, when Hive sees the quotes, it sees the string as a table name. Using quotes (and technically back ticks too, but that's clearly broken) around table names can be allowed/disallowed with a feature in Hive called "hive.support.quoted.identifiers". This feature is enabled in the user's HS2 session by default. However, when performing masking, it is a multi step process:
The query is parsed by HS2
The masking is applied
The query is parsed again by HS2
The first parsing attempt respects the hive.support.quoted.identifiers configuration and allows a query with quotes to be parsed. However, the masking code does not pass this configuration information to the parser on the second attempt. And oddly enough, if the configuration information is not passed along, the parser will consider this feature to be disabled. So, it's actually on the second pass that it fails because the parser rejects the quotes.
For the record, I hit this issue when I removed the Regex feature, because it forced all quoted strings to be considered table names (and subjected to this feature being enabled/disabled) instead of sneaking by as being considered a Regex. All the masking unit tests failed.