Can you provide error log?

If you need static site to introduce your product or other things you can use landing builders, for example, tilda.cc, wix.com and ect Usually building iu by html/css/js spend a lot of time, but you can do it very quickly in UI with landing builders

What kind of configuration of ELK cluster do you have? For example, 3 nodes of elasticsearch, 2 nodes of logstash, 1 node of kibana? Elasticsearch is java application, you can configure heap settings to limit it. Something like this -Xms2g -Xmx2g and try to test it. Of course do it on dev stand )

We are using ant.design, but not with next js. And.design has good integration with React. You can try integrate it with next js

You can try other solutions for it, for example, graylog or splunk? How much limit of memory do you have? How much logs per second do you have?