Telegram telethon messages forwarding bot stopped working

starting from yesterday’ afternoon my messages forwarding bot stopped to work from grabbing messages from channels, but it seems to work with channels where I am admin. In a few words these code lines (I’m omitting all the previous standard code lines where the client starts)

@client.on(events.NewMessage())
async def handler(event):
    print(event)

are not catching messages if new messages are posted in channels that I follow. Anyone got the same issue?
Do you know if something changed and the channels now can block this kind of events?
Thank you