Vertcat error when Im not using vertcat

I am working on a rotational robot homogeneous transformation matricies but I keep getting a vertcat error when Im only multiplying mtrices of the same size. This code was working two weeks ago but all of sudden, its getting a vertcat error. Here is my code:

 function H = H(theta1, theta2, theta3)    %creating homogeneous function
    %--------------------------
    %--------------------------
    H = (Rx(-90)*Rz(theta1)*Tz(0.25))*(Rz(theta2)*Tx(0.4))*(Rz(theta3)*Tx(0.4));
    %there are other parts of this function that simply plot parts of H that I don't belevie are necessary here
 end
 
  %basic transformation functions
  %Rotational martices
  function [Rx] = Rx(a)             %creating functoin Rx
    Rx = [1 0 0 0;                  %defining function Rx
          0 cosd(a) -sind(a) 0;
          0 sind(a) cosd(a) 0;
          0 0 0 1];
  end
  function [Ry] = Ry(b)             %creating functoin Ry
    Ry = [cosd(b) 0 sind(b) 0;      %defining function Ry
          0 1 0 0;
          -sind(b) 0 cosd(b) 0;
          0 0 0 1];
  end
  function [Rz] = Rz(g)             %creating functoin Rz
    Rz = [cosd(g) -sind(g) 0 0;     %defining function Rz
          sind(g) cosd(g) 0 0;
          0 0 1 0;
          0 0 0 1];
  end
  %Tranlational matrices
  function [Tx] = Tx(a)             %creating functoin Tx
    Tx = [1 0 0 a;                  %defining function Tx
          0 1 0 0;
          0 0 1 0;
          0 0 0 1];
  end
  function [Ty] = Ty(b)             %creating functoin Ty
    Ty = [1 0 0 0;                  %defining function Ty
          0 1 0 b;
          0 0 1 0;
          0 0 0 1];
  end
  function [Tz] = Tz(c)             %creating functoin Tz
    Tz = [1 0 0 0;                  %defining function Tz
          0 1 0 0;
          0 0 1 c;
          0 0 0 1];
  end

[Jacob Wood]

I can run the code without issue. Is it possible that H is being called with arguments that are not scalars?

H(0.1,0.2,0.3) % Runs fine
H(0.1,[0.2 0.1],0.3) % Throws vertcat error

[Tina Barsoumian]

YES! that is it, thank you!

[Stephen23]

"Vertcat error when Im not using vertcat"

Actually indirectly you are. This shorthand syntax using square brackets:

[A;B]

calls vertcat to actually perform the concatenation.

As Jacob Wood asked about, the error most likely occurs because some of the arrays you are trying to concatenate are not scalar.