The SPARQL parser fails a FILTER with a trailing dot if it follows a group

ASK 
{
    { }
    FILTER(true) .
}

with an RdfParseException in SparqlQueryParser.TryParseGraphPattern@1309:

[DotToken at Line 5 Column 18 to Line 5 Column 19] Unexpected Token encountered, expected the start of a Graph Pattern

The grammar allows an optional dot after a GraphPatternNotTriples (which includes FILTER).

A real example can be found in the SHACL Test Suite: