There is a new paper from CIMAC WG7.
In February and March 2022, more than 100 ships reported operational problems using high sulphur residual fuels bunkered in Singapore. Ships using these bunkers reported sticking fuel pumps and engine performance failures (high wear in injection equipment) with some ships also reporting separator sludging and filter blocking.
The paper explains the method used for analysis, shows possible root causes, and gives advice to avoid such failures in the future. Download it here