Angular control flow fails during certain cases

[laijuthomas]

Which @angular/* package(s) are the source of the bug?

common

Is this a regression?

Yes

Description

I have a if else block in my html page which was working fine until I upgraded to angular 17 control flow

@if(!isMobile){}
this is how I added the condition, the condition is to show some html based on a boolean variable (which is set using a behaviorsubject). This fails while reloading the page. but when I add an empty @else block, this works without any issue

any idea why this happens?

Please provide a link to a minimal reproduction of the bug

No response

Please provide the exception or error you saw

No response

Please provide the environment you discovered this bug in (run ng version)

Angular CLI: 17.3.6
Node: 20.11.1
Package Manager: npm 10.2.4
OS: darwin arm64

Angular: 17.3.6
... animations, cdk, cli, common, compiler, compiler-cli, core
... forms, platform-browser, platform-browser-dynamic
... platform-server, router, service-worker, ssr

Package                         Version
---------------------------------------------------------
@angular-devkit/architect       0.1703.6
@angular-devkit/build-angular   17.3.6
@angular-devkit/core            17.3.6
@angular-devkit/schematics      17.3.6
@schematics/angular             17.3.6
rxjs                            7.8.1
typescript                      5.3.3
zone.js                         0.14.4

Anything else?

No response

[JoostK]

Please provide a runnable reproduction, as without it we cannot investigate.