Bay window advice re load bearing bay poles and more

[brightbluesky]

I have a 1930's built house and one year ago had the wooden downstairs bay window removed and double glazed window installed.
The window is a one angle type bay, eg flat front window with one angle to wall.
Above the bay window is the bedroom which also has a replacement window, above that is a flat roof with the roof area about 6ft back.
When the downstairs bay window was fitted the company (now no more) failed to fit a load bearing bay pole support on the one angle in the window.
For the past year i have noticed some cracks in the plaster of the upstairs area directly beneath the bay curve area and also running up the area adjacent to the window. This has got slowly greater and has not stopped.
I have sought advice and another glazing company have offered to remove the complete bay window and insert a load bearing bay pole.
My query is this, will this stop the cracking bearing in mind this is only one angle and the rest of the area above the bay eg the 10ft flat window area has no obvious means of support other than the plastic and glass?

 

[stevethejoiner]

It's difficult to answer. A photograph of the elevation and details of floor loading would help. Sometimes windows/walls above bays are also supported by cantilever joists.