ib_insync connection issue

[semiter1]

I got a very strange issue the past week or two. I have problem connecting to IB using ib_insync on a Mac, but without any problem on a PC. Below are some details:

1. The ib_insync code I ran is simple, and the same across systems. The setup for TWS seems to have no issue.

import ib_insync as ibis
ib = ibis.IB()
ib.connect('127.0.0.1', 7497, clientId=1)

Once I ran these three lines on a Mac, the Spyder console keeps running without any error message. I have two Macs, both having the same issue. I have no problem connecting to IB on a PC using this code.

2. I have no issue to connect to IB using IB's own code. That is,

from ibapi.client import EClient
from ibapi.wrapper import EWrapper
class MyWrapper(EWrapper):
def init(self):
super().init()
wrapper = MyWrapper()
client = EClient(wrapper)
client.connect("127.0.0.1", 7497, clientId=1)
client.run()

However, when I ran the ib_insync code above after this, it freezes again. When I restart the kernel, the IB code no longer works, unless I restart the TWS and re login.

3. The ib_insync connect code ran OK about a week ago on one Mac. Then all of a sudden, it stopped working.

Does anyone have a clue about this issue? Many thanks.