ConcurrentModificationException in BrowseController.hasIiifManifest()

The log contains a lot of exceptions like this.

2024-09-23T12:55:44.508Z ERROR 1 --- [nio-8080-exec-1] o.a.c.c.C.[.[.[/].[dispatcherServlet]    : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed: java.util.ConcurrentModificationException] with root cause

java.util.ConcurrentModificationException: null
	at java.base/java.util.LinkedHashMap$LinkedHashIterator.nextNode(LinkedHashMap.java:756) ~[na:na]
	at java.base/java.util.LinkedHashMap$LinkedKeyIterator.next(LinkedHashMap.java:778) ~[na:na]
	at java.base/java.util.AbstractCollection.addAll(AbstractCollection.java:335) ~[na:na]
	at org.apache.cxf.jaxrs.impl.ConfigurationImpl.getInstances(ConfigurationImpl.java:107) ~[cxf-rt-frontend-jaxrs-4.0.5.jar!/:4.0.5]
	at org.apache.cxf.jaxrs.impl.ConfigurationImpl.getContracts(ConfigurationImpl.java:92) ~[cxf-rt-frontend-jaxrs-4.0.5.jar!/:4.0.5]
	at org.apache.cxf.jaxrs.impl.ConfigurationImpl.registerParentProvider(ConfigurationImpl.java:72) ~[cxf-rt-frontend-jaxrs-4.0.5.jar!/:4.0.5]
	at org.apache.cxf.jaxrs.impl.ConfigurationImpl.<init>(ConfigurationImpl.java:57) ~[cxf-rt-frontend-jaxrs-4.0.5.jar!/:4.0.5]
	at org.apache.cxf.jaxrs.client.spec.ClientConfigurableImpl.<init>(ClientConfigurableImpl.java:38) ~[cxf-rt-rs-client-4.0.5.jar!/:4.0.5]
	at org.apache.cxf.jaxrs.client.spec.ClientImpl$WebTargetImpl.<init>(ClientImpl.java:245) ~[cxf-rt-rs-client-4.0.5.jar!/:4.0.5]
	at org.apache.cxf.jaxrs.client.spec.ClientImpl$WebTargetImpl.<init>(ClientImpl.java:239) ~[cxf-rt-rs-client-4.0.5.jar!/:4.0.5]
	at org.apache.cxf.jaxrs.client.spec.ClientImpl.target(ClientImpl.java:110) ~[cxf-rt-rs-client-4.0.5.jar!/:4.0.5]
	at org.apache.cxf.jaxrs.client.spec.ClientImpl.target(ClientImpl.java:120) ~[cxf-rt-rs-client-4.0.5.jar!/:4.0.5]
	at info.textgrid.rep.browse.BrowseController.hasIiifManifest(BrowseController.java:364) ~[!/:4.4.3]
	at info.textgrid.rep.browse.BrowseController.handleXml(BrowseController.java:200) ~[!/:4.4.3]
	at info.textgrid.rep.browse.BrowseController.browse(BrowseController.java:129) ~[!/:4.4.3]
...