Steps to reproduce:
1) Navigate to Monitoring -> Problems;
2) Press "Save as" to save current filter;
3) In Filter properties popup enter following name:

>>>>

4) Press "Save";
5) Observe that tab name is ">>>>";
6) Press on tiny gear icon to open Filter properties popup again;
7) Observe that there is still html entities in name field;
8) Press "Save" without changing anything;

Result:
Tab filter name is changed to html entities. After next page reload it will return to ">>>>".