Function reference declared in unit gives internal error 2019022201

Declaring a function reference in a record from a unit gives internal compiler error 2019022201. Something is wrong with the PPU. This works if declared from a program.

Free Pascal Compiler version 3.3.1 [2022/05/27] for aarch64.

{$mode objfpc}
{$modeswitch functionreferences}

unit function_ref_error;
interface

type
 TCallback = record
   proc: reference to procedure;
 end;

implementation
end.