Unrequired icons

As far as I can tell it is using fontawsome 5 Icons. They appear on all other layouts correctly see as indicated on the attached example of the event detail layout on attached 1.
However on the calendar view when the 'add event icon' is selected in the settings for the page I get the red/white cross and the other illegible one see attached 2.

@hekla
EDIT: I hope, hekla has you a solution

?

Still not been able to solve this.
Helix Ultimate doesn't seem to be the problem because even swapping over to the standard Casseopea for the calendar view the problem is still there.
I have tried editing the php but the offending boxes still remain. I can remove the code for the 'create new event' it removes both icon and offending image. I have tried using a different image file and just text but the boxes are still there.
See attached

PROBLEM SOLVED
I found these offending lines of code (in red below) in file:-
\media\com_jem\css\
Note 'Font Awesome 6 Free' !
.daynum a::after {
content:"\f08e";
font-size: 10px;
padding-left: 5px;
font-family:var(--fa-style-family,"Font Awesome 6 Free");
font-weight:var(--fa-style,900);
content: "\f35d";
}

As far as I can see if you request the 'Red Cross' icon and use that for the 'Add Event' access these are superflous anyway!

only to say:
there are two combined signs (it's not the best)
one is the "plus" and the sign for "link to an other window"-->leads to "submit new event"
the other is (only when there are events on that day) the "day number" and the sign for "link to an other window" ---leads to the day view of the day with this number!