To reproduce (and also version data):
1) Create new project - as an example, let's say, with 5.6.0b1
2) Now close it, then open with 5.6.0b2
3) Notice that it reports saved project's version as 5.6.0b1
4) After finishing opening it up, close it, then open with 5.6.0b3
5) Notice that it still keeps reporting the saved version as 5.6.0b1, even though it was opened with b2
6) After finishing opening it up, close it, and now try opening it with two versions backwards - a6 and a5
7) Notice that the saved project version is staying as 5.6.0b1
8) Try opening it with 5.6.0a1 and then go version by version up
9) Notice that 5.6.0a1 is saved correctly when opening the project with 5.6.0a2, but it gets stuck so, as when opening it with 5.6.0a3 afterwards, the saved project version is still kept as 5.6.0a1
10) Now open this with 5.5.0p4 and p3
11) Notice that the 5.6.0a1 reporting is still stuck. This version actually sticks up to 5.5.0a1
12) Upon opening the project with 5.5.0a1, the saved version gets overwritten correctly, but then opening it with 5.5.0a2 and a3 again shows the bug as it reports saved version as 5.5.0a1 each time, just like in step 9
13) Now open it with 5.4.4p1, f1 and 5.4.3p4
14) This time saved version is reported correctly each time, proving that this is a REGRESSION starting from 5.5