IntelliJ constantly indexing, when src file is in focus - intellij-idea

Question

I have a strange behavior of intellij.
It is constantly trying to reindex my project, as soon as i focus a src file like *.java.
This happens for any project. Even if i have a new project with a single src file.
I have resetted it to manufacturer state and it still tries to reindex.
I am on Ubuntu 18.04
Log output:
2020-08-18 05:02:02,004 [ 260523] INFO - indexing.UnindexedFilesUpdater - Unindexed files update started: 0 files to index
2020-08-18 05:02:02,602 [ 261121] INFO - pl.ProjectRootManagerComponent - project roots have changed (stacktrace has been already reported with trace_hash = 676357740)
2020-08-18 05:02:02,609 [ 261128] INFO - .diagnostic.PerformanceWatcher - Pushing properties took 3ms; general responsiveness: ok; EDT responsiveness: ok
I found this exception in logs which seems to be the root cause
2020-08-18 05:11:52,721 [ 126435] INFO - pl.ProjectRootManagerComponent - project roots have changed (trace_hash = 30135350)
java.lang.Throwable
at com.intellij.openapi.roots.impl.ProjectRootManagerComponent.synchronizeRoots(ProjectRootManagerComponent.java:306)
at com.intellij.openapi.roots.impl.ProjectRootManagerComponent.fireRootsChangedEvent(ProjectRootManagerComponent.java:210)
at com.intellij.openapi.roots.impl.ProjectRootManagerImpl.fireRootsChanged(ProjectRootManagerImpl.java:428)
at com.intellij.openapi.roots.impl.ProjectRootManagerImpl.access$200(ProjectRootManagerImpl.java:37)
at com.intellij.openapi.roots.impl.ProjectRootManagerImpl$BatchSession.rootsChanged(ProjectRootManagerImpl.java:96)
at com.intellij.openapi.roots.impl.ProjectRootManagerImpl.makeRootsChange(ProjectRootManagerImpl.java:371)
at com.intellij.openapi.roots.impl.ProjectRootManagerImpl$RootProviderChangeListener.rootSetChanged(ProjectRootManagerImpl.java:668)
at jdk.internal.reflect.GeneratedMethodAccessor532.invoke(Unknown Source)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:566)
at com.intellij.util.EventDispatcher.dispatchVoidMethod(EventDispatcher.java:123)
at com.intellij.util.EventDispatcher.lambda$createMulticaster$1(EventDispatcher.java:86)
at com.sun.proxy.$Proxy174.rootSetChanged(Unknown Source)
at com.intellij.openapi.roots.impl.RootProviderBaseImpl.fireRootSetChanged(RootProviderBaseImpl.java:47)
at com.intellij.openapi.application.impl.ApplicationImpl.runWriteAction(ApplicationImpl.java:980)
at com.intellij.openapi.projectRoots.impl.ProjectJdkImpl$MyRootProvider.rootsChanged(ProjectJdkImpl.java:291)
at com.intellij.openapi.projectRoots.impl.ProjectJdkImpl.copyTo(ProjectJdkImpl.java:267)
at com.intellij.openapi.projectRoots.impl.ProjectJdkImpl.commitChanges(ProjectJdkImpl.java:309)
at com.intellij.codeInspection.magicConstant.MagicConstantInspection.lambda$attachAnnotationsLaterTo$1(MagicConstantInspection.java:182)
at com.intellij.openapi.application.TransactionGuardImpl$2.run(TransactionGuardImpl.java:201)
at com.intellij.openapi.application.impl.ApplicationImpl.runIntendedWriteActionOnCurrentThread(ApplicationImpl.java:802)
at com.intellij.openapi.application.impl.ApplicationImpl.lambda$invokeLater$4(ApplicationImpl.java:322)
at com.intellij.openapi.application.impl.FlushQueue.doRun(FlushQueue.java:84)
at com.intellij.openapi.application.impl.FlushQueue.runNextEvent(FlushQueue.java:132)
at com.intellij.openapi.application.impl.FlushQueue.flushNow(FlushQueue.java:47)
at com.intellij.openapi.application.impl.FlushQueue$FlushNow.run(FlushQueue.java:188)
at java.desktop/java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:313)
at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:776)
at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:727)
at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:721)
at java.base/java.security.AccessController.doPrivileged(Native Method)
at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85)
at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:746)
at com.intellij.ide.IdeEventQueue.defaultDispatchEvent(IdeEventQueue.java:967)
at com.intellij.ide.IdeEventQueue._dispatchEvent(IdeEventQueue.java:839)
at com.intellij.ide.IdeEventQueue.lambda$dispatchEvent$8(IdeEventQueue.java:450)
at com.intellij.openapi.progress.impl.CoreProgressManager.computePrioritized(CoreProgressManager.java:744)
at com.intellij.ide.IdeEventQueue.lambda$dispatchEvent$9(IdeEventQueue.java:449)
at com.intellij.openapi.application.impl.ApplicationImpl.runIntendedWriteActionOnCurrentThread(ApplicationImpl.java:802)
at com.intellij.ide.IdeEventQueue.dispatchEvent(IdeEventQueue.java:497)
at java.desktop/java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:203)
at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:124)
at java.desktop/java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:113)
at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:109)
at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
at java.desktop/java.awt.EventDispatchThread.run(EventDispatchThread.java:90)

Answer 1

It is known issue: IDEA-247322. The workaround is to disable Preferences | Editor | Inspections | Java | Probable bugs | Magic Constant inspection.
UPD: It is fixed with the 2020.2.3 IDE update.

Answer 2

I found the issue, but i cannot explain it to myself.
I installed intellij over snap. This installation (not the settings) itself was causing this. This was reproducable by reinstalling over snap.
If i install the same build of intellij without snap, the issue does not occur.