mail account problem combination 2 accounts saved mails

hey all,

i have a strange problem:

I have 2 mailaccounts on my huawei.

No problem so far.

On my mail app on the pc and tablet i made some maps to save mails, comming from the 2 accounts.

Again no problem so far.

I recieve and send mails, no problem with that, but when i want to browse to my saved mails ( in folders) , i see i miss some mails comming from one specific account.. But not all is missing just some particular mails.

When i open the mailapp on the pc or tablet , nothing is missing...

the tablet is an ipad , the pc is windows 10, ofcourse the Phone is android.

Is there anyone having the same issue or someone with a sollution?

Thanks in advance.