Cannot open pdf attachments from Iphone mail app

Hi, For some time now ( i am not sure if this happened after an upgrade) i cannot view or download any pdf attachments from my default mail app. i have try from different mail accounts and it is not an account matter. when press the Tap to Download button it shows the circle with down arrow which mean downloading only for a moment and then again the Tap to Download button. I have check also in files and there is no file downloaded. Note that pdf files in my files folder are opened normally. Any advice?

Thanks in advance