Cannot print priority mail, Can print first class

[railroadtreasures]

When using bulk shipping, we entered all the weight and the class of mail (priority, first or media).  After we pay, we get the message 10 of your labels were printed, 2 labels can not be printed.   The ones that are not printed are always priority mail.  We can print them individually.    Ebay customer service is able to print the labels using bulk shipping.   We have tried different omputers, browsers, uninstalled and reinstalled chrome, cleared the cache.   This has been happening for over a month.  Any ideas?

[railroadtreasures]

Tried printing priority labels from my cell phone, with router unplugged and wifi off, using my phone service, still can not print priority labels using bulk mailing. Can print first class and media mail using bulk mailing option.