I've noticed something similar.

The pending deposit was the last payment I received from the pool I was mining NOBL. The switch happened as this deposit had around 90 of 120 confirmations (was stated in the overview). A few hours later it changed to the view like you can see on the screenshot. What do I need to do in order to get those pending coins?
So you have not received those coins before the switch? Could you enter your address into old block explorer and check if/when it shows this last amount for your address?
https://chainz.cryptoid.info/noblold/address.dws?9mpAe8XRjwFKzdqrk1ZTn1B3iF1yQ6qJU4.htmHope that helps.
1. You can see both old and new explorers show same amount of coins. This means there were no late payments on old blockchain into this address.
New block explorer:
https://chainz.cryptoid.info/nobl/address.dws?9mpAe8XRjwFKzdqrk1ZTn1B3iF1yQ6qJU4.htm2. Then at block height 3260 total amount of 479,955.78503217 NOBL was transferred to new address. This shows whoever was controlling 9mpAe8XRjwFKzdqrk1ZTn1B3iF1yQ6qJU4 was able to access coins on new blockchain.
So what exactly is the problem? Everything looks good.