Trailing slash is gone.

[Aco-gt]

Trailing slash is gone.
There is no problem with other mail clients. Does anyone have a solution?
In most cases, the hyper link works well but sometimes the hyper link had same issue.
I have attached the pics, please take a look at it.

RAINLOOP v1.17.0
Server OS: Amazon Linux release 2 (Karoo)
PHP 8.0.25
Windows Google Chrome

NG RAINROOP (Trailing slash is gone.)

OK Thunderbird