An occasional problem：Unable to load implementation class JsonFormat

I have a cluster that deploys the same image, with a total of six nodes. Occasionally, some nodes do not load the JsonFormat class,
The relevant codes are as follows

EventFormat eventFormat = EventFormatProvider.getInstance()
                    .resolveFormat(JsonFormat.CONTENT_TYPE);
            if (eventFormat == null) {
                logger.info("resolveFormat failed,force retry..");
                eventFormat = new JsonFormat().withForceNonJsonDataToString();
                if (eventFormat != null) {
                    logger.info("resolveFormat failed,retry success..");
                }
                EventFormatProvider.getInstance().registerFormat(eventFormat);
                return eventFormat;

i observed that the SPI mechanism did not take effect on the problem node and manually instantiated the successful log of the JsonFormat class.
I can't understand why this situation occurs. It occurs relatively infrequently, but it does exist. The current solution is not elegant enough, and I hope to receive help.

this is my version

Start by tracing EventFormatProvider.getInstance().resolveFormat(JsonFormat.CONTENT_TYPE), the JsonFormat implementation, and the SPI registration path. Compare behavior on affected and healthy nodes using the reported deployment and version. Done means the intermittent loading failure is reproduced or explained and a concrete corrective change is identified.