> list "static-bug.bas"
Option Explicit On
Option Default None
Option Base 0

If foo%(10)         = 11 Then Print "1: PASS" Else Print "1: FAIL"
If bar_1%(11)       = 11 Then Print "2: PASS" Else Print "2: FAIL"
If bar_1%(0)        = 11 Then Print "3: PASS" Else Print "3: FAIL"
If bar_2%(foo%(10)) = 11 Then Print "4: PASS" Else Print "4: FAIL"
If bar_2%(0)        = 11 Then Print "5: PASS" Else Print "5: FAIL"

Function foo%(a%)
  foo% = a% + 1
End Function

Function bar_1%(b%)
  Static static_1% = -1
  If static_1% = -1 Then static_1% = b%
  bar_1% = static_1%
End Function

Function bar_2%(c%)
  Static static_2% = -1
  If static_2% = -1 Then static_2% = c%
  bar_2% = static_2%
End Function

> run
1: PASS
2: PASS
3: PASS
4: PASS
5: FAIL