Query parser: =< confuses parser

On the IndiScale demo server, the following query confuses the parser:

query=FIND Record Analysis WITH date =< 2019-05-16

The server returns this message:

  <Query string="FIND Record Analysis WITH date =&lt; 2019-05-16" results="0">
    <ParseTree>
      <ParsingError type="AttemptingFullContext">AttemptingFullContext conflict in query. Please report this with a bug ticket.</ParsingError>
      <ParsingError type="Ambiguity">Ambiguity conflict in query. Please report this with a bug ticket.</ParsingError>
      <ParsingError type="SyntaxError" line="1" character="32">mismatched input '&lt;' expecting {&lt;EOF&gt;, SINGLE_QUOTE_START, DOUBLE_QUOTE_START, WITH, A, WHERE, WHICH, HAS_A, '#', STAR, DOT, '-', NUM, TXT}</ParsingError>
    </ParseTree>
    <Role />
    <Entity />
    <TransactionBenchmark since="Tue Oct 01 15:52:15 CEST 2019" />
  </Query>