Hi there,
I also have the exact same problem. Interestingly, after I tried to fetch the data via API from TWS and didn't get the prices though (I always got the message that the "requested market data is not subscribed"), the TWS seems to "lock" this strike/expiry date combination of this symbol. If I load the option chain in TWS, the combinations for which I didn't receive the data have blank lines and a link to the market data manager. This can only be fixed with a restart of the TWS.
Did someone found a solution for solving this problem? Did a downgrade to 9.73 (where did you get it from?) solved the issue?
Thanks a lot!
Andreas
