You need to select correct solver configuration. Take solver type Fixed step and make sure the fixed step size is relatively small compared to the repeating sequence signal time period for better accuracy (Since it takes more steps to construct the signal)
Change solver type to Fixed Step and Fixed -step size to 1/1000/20
For repeating sequence block Take time values as [1/1000/4 1/1000/2 3/1000/4 1/1000]
output values as [0 1 0 -1 0]
Here i am generating a triangular waveform whose frequency is 1000Hz and solver takes 20 steps to constuct each cycle of the waveform.