Thanks for the prompt reply.
I have a client who tends to reply after quite a long while. I am not complaining about it. I can understand she might be busy in something. So, recently (5th Sept.) I had received an email from Upwork that there had been no activity for the past 75 days which would eventually result in the closure of contract after 14 days. I am aware of the whole thing that Upwork cannot keep funds in escrow for over 90 days.
The last 14-day period of the contract was supposed to end on 19th. I had been trying to contact the client in every way known to me, but she didn't seem to be available. I can understand that there could be some serious reason why she has not been replying, so I am not blaming her in any manner. However, as discussed with the client earlier, there were some additions to be made to the existing contract, and for this reason, I did not want the contract to end. So, I formally submitted the work in the contract room and requested the funds, not necessarily for the sake of the funds but to see if it counts as an activity and prevents the contract to end on its own.
And, it seems to have worked. It's already 21st of September in my timezone, i.e., about two days past the date on which the contract was supposed to end due to lack of "activity". The client has not responded to my request, neither has released any funds; no messages or anything to indicate that she is available on the platform. But, the contract is still intact, it has not ended.