we have deployed a spring boot 3 application behind an nginx server. the nginx configuration is as follows:

location ~ ^/api(/|$) {     
        proxy_pass http://127.0.0.1:8080;  # Forward requests to backend server
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection 'upgrade';
        proxy_set_header Host $host;
        proxy_cache_bypass $http_upgrade;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header X-Forwarded-proto https; 
    proxy_set_header X-Forwarded-Prefix /api/; 
    }

with this setup we observe following error randomly and infrequently but consistently in spring boot logs:

2024-04-30T21:15:17.874Z  INFO 3992 --- [nio-8080-exec-7] o.apache.coyote.http11.Http11Processor   : Error parsing HTTP request header
 Note: further occurrences of HTTP request parsing errors will be logged at DEBUG level.

java.lang.IllegalArgumentException: Invalid character found in method name [0x160x030x010x000xee0x010x000x000xea0x030x03]0x850xe10xe00x080xba~PE0x1bN0xdc0x8f?0x1fw:~C0xc3q0xbb0xb90x88l0xb00xd50x8d0x9a0xcc= ]. HTTP method names must be tokens
    at org.apache.coyote.http11.Http11InputBuffer.parseRequestLine(Http11InputBuffer.java:407) ~[tomcat-embed-core-10.1.15.jar:10.1.15]
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:264) ~[tomcat-embed-core-10.1.15.jar:10.1.15]
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:63) ~[tomcat-embed-core-10.1.15.jar:10.1.15]
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:896) ~[tomcat-embed-core-10.1.15.jar:10.1.15]
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1744) ~[tomcat-embed-core-10.1.15.jar:10.1.15]
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:52) ~[tomcat-embed-core-10.1.15.jar:10.1.15]
    at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191) ~[tomcat-embed-core-10.1.15.jar:10.1.15]
    at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659) ~[tomcat-embed-core-10.1.15.jar:10.1.15]
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) ~[tomcat-embed-core-10.1.15.jar:10.1.15]
    at java.base/java.lang.Thread.run(Thread.java:1583) ~[na:na]

I did some googling and the afaiu most people say this error happens when a https request is being made to a server that expect http instead. our config shows that we do terminate tls at nginx:

proxy_http_version 1.1;

has anyone experienced this and knows how to fix?