Question: The "simplify" command is garbage !

Hi !
I have been working for a long time to evaluate several infinites summations .
I often use a command like  "simplify(combine(sum1-sum2))"  to check if both summations are equal .
Now ,I found that the "simplify" command is not reliable at all . Check my file "" .
I have Maple 2017 and 2018 on Windows 10 .
I'm angry because I have to double check all of my work trying not to use this buggy command.
If someone can confirm that the 2020 version of Maple has an improved "simplify" command , I will buy it immediately.
Thank you !
Please Wait...