CentOS下 dotnet: command not found

CentOS 8,之前装的2.1是正常的，然后卸载了，再装了3.1的SDK就炸了,始终command not found

[root@iZwz9883ha8ul4wcjros0tZ /]# sudo dnf install dotnet-sdk-3.1 
Last metadata expiration check: 2:55:32 ago on Sat 29 Aug 2020 06:44:23 PM   CST. Package dotnet-sdk-3.1-3.1.401-1.x86_64 is already installed. 
Dependencies resolved. 
Nothing to do. 
Complete! 
[root@iZwz9883ha8ul4wcjros0tZ /]# dotnet --info
 -bash: dotnet: command not found 
[root@iZwz9883ha8ul4wcjros0tZ /]# whereis dotnet
 dotnet: /usr/bin/dotnet /usr/lib64/dotnet /etc/dotnet /usr/local/bin/dotnet /usr/share/dotnet /usr/share/man/man1/dotnet.1.gz 
[root@iZwz9883ha8ul4wcjros0tZ /]# ls /usr/bin/dotnet/sdk 
 3.1.401 
[root@iZwz9883ha8ul4wcjros0tZ /]# ls /usr/lib64/dotnet
 host packs shared 
[root@iZwz9883ha8ul4wcjros0tZ /]# ls /usr/local/bin/dotnet/sdk
 3.1.401 
[root@iZwz9883ha8ul4wcjros0tZ /]# ls /usr/share/dotnet/sdk
 3.1.401 
[root@iZwz9883ha8ul4wcjros0tZ /]#
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