An announcement explains that as of Jan 22nd CurveGlobal will cease trading:

CurveGlobal limited has announced that, following a strategic review of the business, the decision has been taken to wind down the company. London Stock Exchange plc has advised its CurveGlobal Markets members that it will cease trading in all CurveGlobal products at 18.00 on 28 January 2022. CurveGlobal Markets will work with members to manage the transfer or closure of all open interest in these contracts as efficiently as possible. We encourage member firms to trade out of open positions ahead of the final trading day.' 

Andy Ross (CEO) had this to say:

It’s a shame, but, unfortunately we told the market, yesterday evening, that we were closing CurveGlobal. Our priority is to help all the clients manage out of positions as best they can before the end of Jan 22. 

I wanted to take this moment to thank all those that have worked with us, traded with us and shared encouragement, advice and support. 

We’re here to help you close out positions – and manage the LIBOR to SONIA transition.

Official market notice here.

Post annoucement commentary from Andy here.

It's a shame as Andy and the team worked hard to differentiate their platform and try to attract volume, plus risk offsets with LCH.