I am using this repo to recreate a problem with Angular Material Tooltips where the tooltip displays and then immediately disappears after hovering over the element. This occurs only when using matTooltipClass and only in an Angular SPA running under .NET Core that was created using the dotnet angular template.

The problem was caused by an interaction with bootstrap. The following is found here:

The outermost wrapper element should have the .tooltip class and role="tooltip".

I renamed my class from .tooltip to .rg-tooltip to fix it:

• run dotnet new angular from the project directory.

• run dotnet new sln followed by dotnet sln dotnetcorengspa.sln add dotnetcorengspa\dotnetcorengspa.csproj from the parent directory.

• run ng update @angular/core@8 @angular/cli@8 to clean up dependencies.

• run ng add @angular/material.

• Create class selector (.tooltip) in global styles for tooltips.

• Create a couple of buttons on the home page using Material. Assign tooltips to both and use matTooltipClass to assign tooltip class to one.

• Update to Angular/Material V9

  • Run npm install tslib --save to intall tslib dependency.
  • Running ng update @angular/core@9 @angular/cli@9 results in the following at this point:

  Using package manager: 'npm'
  Collecting installed dependencies...
  Found 42 dependencies.
  Fetching dependency metadata from registry...
      Updating package.json with dependency @angular-devkit/build-angular @ "0.901.15" (was "0.803.29")...
      Updating package.json with dependency @angular/cli @ "9.1.15" (was "8.3.29")...
      Updating package.json with dependency @angular/compiler-cli @ "9.1.13" (was "8.2.14")...
      Updating package.json with dependency @angular/language-service @ "9.1.13" (was "8.2.14")...
      Updating package.json with dependency typescript @ "3.8.3" (was "3.5.3")...
      Updating package.json with dependency @angular/animations @ "9.1.13" (was "8.2.14")...
      Updating package.json with dependency @angular/common @ "9.1.13" (was "8.2.14")...
      Updating package.json with dependency @angular/compiler @ "9.1.13" (was "8.2.14")...
      Updating package.json with dependency @angular/core @ "9.1.13" (was "8.2.14")...
      Updating package.json with dependency @angular/forms @ "9.1.13" (was "8.2.14")...
      Updating package.json with dependency @angular/platform-browser @ "9.1.13" (was "8.2.14")...
      Updating package.json with dependency @angular/platform-browser-dynamic @ "9.1.13" (was "8.2.14")...
      Updating package.json with dependency @angular/platform-server @ "9.1.13" (was "8.2.14")...
      Updating package.json with dependency @angular/router @ "9.1.13" (was "8.2.14")...
      Updating package.json with dependency zone.js @ "0.10.3" (was "0.9.1")...
    UPDATE package.json (1751 bytes)
  ? Installing packages (npm)...npm ERR! code ERESOLVE
  npm ERR! ERESOLVE unable to resolve dependency tree
  npm ERR!
  npm ERR! Found: @angular-devkit/[email protected]
  npm ERR! node_modules/@angular-devkit/build-angular
  npm ERR!   dev @angular-devkit/build-angular@"^0.901.15" from the root project
  npm ERR!
  npm ERR! Could not resolve dependency:
  npm ERR! dev @angular-devkit/build-angular@"^0.901.15" from the root project
  npm ERR!
  npm ERR! Conflicting peer dependency: @angular/[email protected]
  npm ERR! node_modules/@angular/compiler-cli
  npm ERR!   dev @angular/compiler-cli@"^9.1.13" from the root project
  npm ERR!   peer @angular/compiler-cli@">=9.0.0 < 10" from @angular-devkit/[email protected]
  npm ERR!   node_modules/@angular-devkit/build-angular
  npm ERR!     dev @angular-devkit/build-angular@"^0.901.15" from the root project
  npm ERR!
  npm ERR! Fix the upstream dependency conflict, or retry
  npm ERR! this command with --force, or --legacy-peer-deps
  npm ERR! to accept an incorrect (and potentially broken) dependency resolution.
  npm ERR!
  npm ERR! See C:\Users\ray\AppData\Local\npm-cache\eresolve-report.txt for a full report.
  
  npm ERR! A complete log of this run can be found in:
  npm ERR!     C:\Users\ray\AppData\Local\npm-cache\_logs\2021-03-24T18_55_26_222Z-debug.log
  ? Package install failed, see above.
  × Migration failed. See above for further details.
  

  • The only way I was able to work around this was to run npm install --force. The ng update does update the package.json file but npm fails. Using --force allows it to complete. Things look OK.
  • Run ng update @angular/core@9 @angular/cli@9 again to be sure.

  Using package manager: 'npm'
  Collecting installed dependencies...
  Found 42 dependencies.
  Fetching dependency metadata from registry...
  Package '@angular/core' is already up to date.
  Package '@angular/cli' is already up to date.
  

  • Run ng update @angular/material@9.

• Site works. Problem persists.

• Upgrade to Angular/Material V10.

  npm uninstall @nguniversal/module-map-ngfactory-loader
  ng update @angular/core@10 @angular/cli@10
  npm install --force
  ng update @angular/material@10
  

  • Remove import of ModuleMapLoaderModule from '@nguniversal/module-map-ngfactory-loader'.

• Site works. Problem persists.

• Upgrade to Angular/Material V11.

  ncu -u codelyzer
  npm install
  git commit -a
  ng update @angular/core@latest @angular/cli@latest
  npm install --force
  ng update @angular/material@11
  

• Site works. Problem persists.

I've done as little as possible to the original code created by the dotnet angular template in order to recreate the problem. The problem persists even after updating to the latest angular/material, including updating remaining packages.