If it is "standard" sql then this linked page explains what underscores in a LIKE statement normally mean, and how to escape them.
https://learn.microsoft.com/en-us/sql/t-sql/language-elements/wildcard-match-one-character-transact-sql?view=sql-server-ver16
--THIS SHOULD WORK
WHERE a.[workspc_nm] LIKE 'E[_]';
--YOU CAN ALSO TRY SPECIFYING THE ESCAPE CHARACTER INSTEAD OF BACKSLASH - LIKE THIS
WHERE a.[workspc_nm] LIKE 'E$_' ESCAPE '$';
WHERE a.[workspc_nm] LIKE 'E^_' ESCAPE '^';
-- THIS MAY ALSO WORK - THE FIRST BACKSLASH ESCAPES THE SECOND
where a.[workspc_nm] LIKE 'E\\_%'
