The linetype hasn't been created properly.
you will probably find the linetype definition is wrong.
Look in your acadiso.lin file probably located somewhere like

you will probably something like
*SANITARY_LINE2,SEWER line ---SAN---SAN---SAN---SAN
A,12.7,-5.08,["SAN",STANDARD,S=10.54,U=0.0,X=-10.54,Y=-1.27],-6.35
which would give a line looking like yours

instead of something like
*SANITARY_LINE,SEWER line ---SAN---SAN---SAN---SAN
A,12.7,-5.08,["SAN",STANDARD,S=2.54,U=0.0,X=-2.54,Y=-1.27],-6.35
which would give a line without the letters interfering with each other

I have attached a course booklet I wrote in 2007, which explains how linetypes are created
look at page 23 which explains how to set up the text correctly.
Michael Kovacik
2d & 3d Autocad and Inventor designer/draughtsman/trainer
Inventor Pro 2018; Autocad 2018
.
Johannesburg, South Africa
.
(Impossible only means you haven't
found the solution yet)