Format>Parag shows Alt_Shift_P as shortcut key; yet, Tools>Customize>keyboard shows no attribution for Alt_Shift_P.
Alt+Shift+P is Format -> Page Style, right? I can confirm in LO 7.5.0.0.alpha0+ (cfc8a8f5d841b3f84d207196153be67da7f60652) / Ubuntu. Same with Styles -> Edit Style..., which opens the Paragraph Style dialog, the accelerator is Alt+P. These accelerators were added in: https://cgit.freedesktop.org/libreoffice/core/commit/?id=856887cbc8a0a2fd04b90ee2170948d34c8ff9c4
These shortcuts were set globally, not just for Writer, therefore one need to switch to the "LibreOffice" context (instead of "Writer") at the top right part of the dialog to see their assignment. But I think that setting them globally was wrong, as at least the Page Style command is Writer specific.
(In reply to Aron Budea from comment #1) > Alt+Shift+P is Format -> Page Style, right? Yes. Sorry.