I got an email from the exchange I use stating the Istanbul hard fork is to occur at block 9069000 at approximately 15:44:36 PST on December 7. It happened already but they have suspended all deposits and withdrawals from happening until further notice.
It is not a contentious fork and so does not result in any new coins from it happening.
So why would they decide to suspend all transactions of ethereum?
Ethereum hard fork Istanbul took place. Serious exchanges have suspended the entry of ETH withdrawal to reduce the risks relating to the funds of their customers. ETH network 60% switched to new changes. We need to wait for the announcement of the restoration of input ETH output.