[kr0bat]

Thank for for linking. This confirms that yes...

    The OECD said the decline was not inevitable, pointing to Singapore, where students scored the highest in maths, reading and science, with results that suggested they were on average three to five years ahead of their OECD peers.

    After Singapore, Macau, Taiwan, Hong Kong, Japan and South Korea also outperformed in maths and science, where Estonia and Canada also scored well.

Reuters DID conflate "doing better" with "not doing worse". I believe OECD pointed to Singapore because their scores were high AND INCREASING.

A quick scan of I.5.1 shows Macau, Canada, Hong Kong, and Estonia with worse scores compared to 2018. Singapore and Japan's scores went up. A less lazy reader can use the OECD database to find numbers for the other listed countries.