Practice challenges not working?

I have been trying to submit a solution to the " Cersei and her Soldiers" practice challenge.
The on-site compiler seems to be rejecting the code with spurious errors.
The code submitted compiles and runs with correct results in Visual Studio Ent 2019.
This is the second solution I have submitted that has been similarly rejected.

Please advise.

i did not submit any code of abv prob
and you hav posted link to prob and ur solution
how people are gonna help you ?

Thanks for your reply Ganesh.
I want someone in the dev team to look into the problem.
Code that runs fine in Visual Studio is being rejected… ?
What is the point in having these practice challenges if the on-site compiler does not correctly evaluate submitted solutions - this is probably why so few correct solutions have been registered.

I forgot to add -

I am working with C# (.NET 4.6.2)


I found a related thread to my issue.
Got my code to work.
It should be made clear that submitted must be run with custom input - click the checkbox near to the Run button to activate the input panel.

Sorry… more weirdness…
Although my code gives the correct result on the site submit page (with custom input), my code is not being registered as a correct solution.
What the hell is going on here… ???
Is anyone from the dev team interested in this issue?
Give me access to the code and I will fix…
Also, why are all the challenge to do with playing around with numbers and trees?