Titles seem to be completely broken in this version (maybe earlier). To replicate, do
/title @p title {text:"Broken"}
and it should error with
"Invalid JSON: malformed JSON at line 1 and column 3
I could not find any other reports of this issue
Linked issues
Comments 1
JSON formatting became more specific in these snapshots for no apparent reason. Try: /title @p title {"text":"Broken"}