Having just changed to the May release of PBIRS our links in reports that open via a Web URL Action open in a Popup Window.
On IE11 this results in the window not being resizable so the opened report is barely visible.
This wasnt occuring in the January Release.
I will do further analysis on this issue and update here soon.
I've experienced this issue too. I've tracked it down to the offending line of code:
case 5: return r !== k.WebUrl ? [3, 6] : (v = t.webUrl, jsCommon.UrlUtils.isValidHttpUrl(v) && (g = window.open(v, "_blank", "noopener,noreferrer"), g && g.focus()), [3, 14]);
Basically it's an IE bug/feature which you can verify for yourself by running:
window.open(someUrl, "_blank", "noopener,noreferrer")
from the IE11 console.
If you were to include the word "resizable" in the third parameter to window.open() then the problem would go away, but we'll leave that to the Power BI team 🙂
An alternative workaround for the time being is to change the default behaviour for tabs in IE11 to always open in a new tab (rather than a new window):