Debugging does not start at the first line of main

When starting the debugger the first line where the debugging should start on the first line after the main. In the example below i32.const 127. However, once the debugger fully starts, rarely the debugger indicates that line as the debugging starting point. Instead, it indicates an instruction in the loop as the starting point. This happens with any piece of wast code.

I assume somehow that the issue comes from the MCU or emulator first executing some instructions before being paused by the debugger client.

(module
  (type $t0 (func (param i32 i32)))
  (type $t1 (func (param i32) (result i32)))
  (type $t2 (func (param i32 i32 i32)))
  (type $t3 (func (param i32 i32 i32 i32 i32)))
  (type $t4 (func))
  (type $t5 (func (param i32)))

  (import "env" "chip_delay" (func $env.chip_delay (type $t5)))
  (import "env" "chip_pin_mode" (func $env.chip_pin_mode (type $t0)))
  (import "env" "chip_digital_write" (func $env.chip_digital_write (type $t0)))
  (import "env" "chip_digital_read" (func $env.chip_digital_read (type $t1)))
  (import "env" "subscribe_interrupt" (func $env.subscribe_interrupt (type $t2)))
  (import "env" "chip_ledc_setup" (func $env.chip_ledc_setup (type $t2)))
  (import "env" "chip_ledc_attach_pin" (func $env.chip_ledc_attach_pin (type $t0)))
  (import "env" "chip_analog_write" (func $env.chip_analog_write (type $t2)))

  ;; Non-mutable globals
  (global $led i32 (i32.const 10))
  (global $up i32 (i32.const 39))
  (global $down i32 (i32.const 37))

  ;; Mutable globals
  (global $delta (mut i32) (i32.const -127))

  (func $decrease (type $t4)
    i32.const -127
    ;; i32.const 127
    global.set $delta)

  (func $increase (type $t4)
    i32.const 127
    ;; i32.const 0
    global.set $delta)

  (func $setup (type $t4)
    ;; configure pin
    i32.const 0
    i32.const 5000
    i32.const 12
    call $env.chip_ledc_setup
    global.get $led
    i32.const 0
    call $env.chip_ledc_attach_pin
    ;; setup buttons
    global.get $up
    i32.const 2
    i32.const 2
    call $env.subscribe_interrupt
    global.get $down
    i32.const 1
    i32.const 2
    call $env.subscribe_interrupt)

  (func $main (type $t4)
    ;; brightness variable
    (local $brightness i32)
    i32.const 127
    local.set $brightness
    ;; setup hardware
    call $setup
    ;; main loop
    loop $L0
      local.get $brightness
      global.get $delta
      i32.add
      local.set $brightness
      (if (i32.gt_s (local.get $brightness) (i32.const 254))
        (then
          i32.const 254
          local.set $brightness))

      (if (i32.lt_s (local.get $brightness) (i32.const 0))
        (then
          i32.const 0
          local.set $brightness))

      i32.const 0
      local.get $brightness
      i32.const 254
      call $env.chip_analog_write

      i32.const 100
      call $env.chip_delay
      br $L0
    end)

  (table $T0 3 funcref)
  (memory $memory 1)

  (global $g0 (mut i32) (i32.const 2048))
  (global $__data_end i32 (i32.const 2048))
  (global $__heap_base i32 (i32.const 2048))
  (export "memory" (memory $memory))
  (export "main" (func $main))
  (export "__data_end" (global $__data_end))
  (export "__heap_base" (global $__heap_base))
  (elem $e0 (i32.const 1) func $decrease)
  (elem $e1 (i32.const 2) func $increase))

TOPLLab / WARDuino-VSCode

Debugging does not start at the first line of main #55