Object serializing via RTTI doesn't work anymore - delphi

Question

I have 2 years old project which I am rebooting back to life. I have debug window which shows different information, and one part of them is that it serializes various google protobuf objects and shows them.
Here is how typical protobuf class looks like:
// Generated by the protocol buffer compiler. DO NOT EDIT!
// Source: message.proto
unit Poker.Protobufs.Objects.PingParams;
interface
uses
System.SysUtils,
{$IFNDEF FPC} System.Generics.Collections {$ELSE} Contnrs {$ENDIF},
pbOutput, Poker.Protobufs.Objects.Base, Poker.Protobufs.Reader, Poker.Types;
type
TPB_PingParams = class(TProtobufBaseObject)
private
const
kUptimeFieldNumber = 1;
var
FUptime: UInt32;
FHasBits: UINT32;
procedure set_has_Uptime;
procedure clear_has_Uptime;
procedure SetUptime(const AValue: UInt32);
public
constructor Create(const AFrom: TPB_PingParams; const ALightweight: Boolean = FALSE); overload;
destructor Destroy; override;
procedure LoadFromProtobufReader(const AProtobufReader: TProtobufReader; const ASize: Integer); override;
procedure MergeFrom(const AFrom: TPB_PingParams);
procedure Clear;
function IsInitialized: Boolean; override;
// required uint32 Uptime = 1;
function has_Uptime: Boolean;
procedure clear_Uptime;
property Uptime: UInt32 read FUptime write SetUptime;
end;
TPB_PingParamsList = class(TObjectList<TPB_PingParams>)
procedure Assign(const APB_PingParamsList: TList<TPB_PingParams>);
end;
implementation
uses
pbPublic;
constructor TPB_PingParams.Create(const AFrom: TPB_PingParams; const ALightweight: Boolean = FALSE);
begin
inherited Create(ALightweight);
MergeFrom(AFrom);
end;
destructor TPB_PingParams.Destroy;
begin
inherited;
end;
procedure TPB_PingParams.LoadFromProtobufReader(const AProtobufReader: TProtobufReader; const ASize: Integer);
var
tag, field_number, wire_type, endpos: Integer;
begin
endpos := AProtobufReader.getPos + ASize;
while (AProtobufReader.getPos < endpos) and
(AProtobufReader.GetNext(tag, wire_type, field_number)) do
case field_number of
kUptimeFieldNumber: begin
Assert(wire_type = WIRETYPE_VARINT);
FUptime := AProtobufReader.readUInt32;
set_has_Uptime;
end;
else
AProtobufReader.skipField(tag);
end;
end;
procedure TPB_PingParams.MergeFrom(const AFrom: TPB_PingParams);
begin
if AFrom.has_Uptime then
SetUptime(AFrom.Uptime);
end;
function TPB_PingParams.IsInitialized: Boolean;
begin
if (FHasBits and $1) <> $1 then
Exit(FALSE);
Exit(TRUE);
end;
procedure TPB_PingParams.clear_Uptime;
begin
FUptime := 0;
clear_has_Uptime;
end;
function TPB_PingParams.has_Uptime: Boolean;
begin
result := (FHasBits and 1) > 0;
end;
procedure TPB_PingParams.set_has_Uptime;
begin
FHasBits := FHasBits or 1;
end;
procedure TPB_PingParams.clear_has_Uptime;
begin
FHasBits := FHasBits and not 1;
end;
procedure TPB_PingParams.SetUptime(const AValue: UInt32);
begin
if not Lightweight then
Assert(not has_Uptime);
FUptime := AValue;
if not Lightweight then
ProtobufOutput.writeUInt32(kUptimeFieldNumber, AValue);
set_has_Uptime;
end;
procedure TPB_PingParams.Clear;
begin
if FHasBits = 0 then
Exit;
clear_Uptime;
end;
procedure TPB_PingParamsList.Assign(const APB_PingParamsList: TList<TPB_PingParams>);
var
pbobj: TPB_PingParams;
begin
Clear;
for pbobj in APB_PingParamsList do
Add(TPB_PingParams.Create(pbobj, TRUE));
end;
end.
And my serialization function:
function SerializeObject(const AObject: TObject): String;
var
t: TRttiType;
p: TRttiProperty;
properties: TArray<TRttiProperty>;
method: TRttiMethod;
begin
result := '';
if not Assigned(AObject) then
Exit;
t := TRttiContext.Create.GetType(AObject.ClassType);
properties := t.GetProperties;
for p in properties do
begin
method := t.GetMethod(Format('has_%s', [p.Name]));
if (Assigned(method)) and
(method.Invoke(AObject, []).AsBoolean) then
result := result + Format('%s: %s; ', [p.Name, ValueToStr(p, p.GetValue(AObject))]);
end;
end;
It is specifically designed to serialize fields that begin with has_ in protobuf objects. Now, I didn't change anything in the code over last 2 years, and this was working before. But now it doesn't. Line properties = t.GetProperties returns empty array for my protobuf classes.
My guess is that I had some globally defined compiler directive which allowed me to serialize public methods in the class. But I cannot figure out which one.
If I put {$M+} in front of my protobuf classes, and move methods to published, it works (kinda). But this worked before just like it is shown in the sources, without any {$M+} directives or similar. So I'm curious what I miss.
Compiler is same as before, XE2.