the “solution” to runaway memory consumption on a given application will typically be unique for each project (this is why I didn’t state any specific “[look here]” type statements)
most of the time finding a memory leak; which in the majority of cases is a dangling pointer (there are others but they are far more rare, and are often caused by errors in the compiler, or problems with Malloc which is Open Source Read). Where the engine runtime is Garbage Collected there could be some situations there, but they are usually explicit.
in full release versions of the Editor/Engine Epic has assured and asked for our “trust” that the Editor’s pre-built blueprint nodes have the memory management taken care of, so you should focus your efforts on looking into your own C++ (the vast majority of dangling pointers will be the use of new) and instead of combing every *.cpp, and *.h in current times we we use Profiling to figure out where these problems are.
even if your project is “only in blueprints” (because your team only ever made blueprint scripts) your plugins, or store assets could have C++, and that could also be the culprit. In this scenario then you will need to report the issue to the plugin/asset creator.
there is the chance that someone at Epic did make a mistake and forgot to de-allocate memory, which especially for a “Blueprint project” will be found through profiling, but that should be submitted as a “bug report” on these forums (these supposedly tie directly into the Epic Engineering Team’s internal tracking, so as “reproducible as possible” would be most appreciated)