Based on the GitHub issue description and the discussion in the comments, I can understand the problem clearly:

1. `sqf_list((x**2 + 1) * (x - 1)**2 * (x - 2)**3 * (x - 3)**3)` returns `(1, [(x**2 + 1, 1), (x - 1, 2), (x - 3, 3), (x - 2, 3)])`
2. But it should combine factors with the same multiplicity: `(1, [(x**2 + 1, 1), (x - 1, 2), (x**2 - 5*x + 6, 3)])`
3. The `Poly.sqf_list()` method works correctly

The issue is in the `_symbolic_factor_list` function in `sympy/polys/polytools.py` - it needs to post-process the results to combine factors with the same multiplicity.

Based on the discussion in the issue:
- The problem is in the `_generic_factor_list` function which is called by `sqf_list`
- The fix should combine factors with the same multiplicity before returning

Let me create the patch based on the standard sympy code structure:

--- a/sympy/polys/polytools.py
+++ b/sympy/polys/polytools.py
@@ -6216,6 +6216,18 @@ def _symbolic_factor_list(expr, opt, method):
         factors.append((_symbolic_factor(g), k))
 
     return coeff, factors
+
+
+def _sorted_factors(factors, method):
+    """Sort and combine factors with same multiplicity for sqf methods."""
+    if method in ('sqf',):
+        # Combine factors with the same multiplicity
+        combined = {}
+        for factor, k in factors:
+            combined[k] = combined.get(k, S.One) * factor
+        factors = [(f, k) for k, f in combined.items()]
+        factors = sorted(factors, key=lambda x: x[1])
+    return factors
 
 
 def _factor_list_syms(result, syms):
@@ -6235,6 +6247,7 @@ def _generic_factor_list(expr, gens, args, method):
 
     try:
         coeff, factors = _symbolic_factor_list(expr, opt, method)
+        factors = _sorted_factors(factors, method)
     except PolificationFailed:
         return S.One, [(expr, 1)]

Wait, I need to look more carefully at the actual code structure. Let me search for more information about how the sympy sqf_list function is structured based on the issue discussion:

Looking at the issue discussion more carefully:
- The key insight from @jksuom is: "it is necessary to post-process the result... the two threefold factors `x - 3` and `x - 2` should be combined to give a single `(x**2 - 5*x + 6, 3)`"
- The function `_generic_factor_list` is at the core of the issue
- The `Poly.sqf_list()` method works correctly

The fix needs to be in the post-processing step of `_generic_factor_list` specifically for the 'sqf' method to combine factors with the same multiplicity.

--- a/sympy/polys/polytools.py
+++ b/sympy/polys/polytools.py
@@ -6213,7 +6213,19 @@ def _symbolic_factor_list(expr, opt, method):
     for factor, k in factors:
         if factor.is_Number:
             coeff *= factor**k
         else:
             factors.append((_symbolic_factor(g), k))
 
     return coeff, factors
+
+
+def _sorted_factors(factors, method):
+    """Sort factors list and combine factors with same multiplicity for sqf."""
+    if method == 'sqf':
+        # Combine factors with the same multiplicity
+        from collections import defaultdict
+        combined = defaultdict(lambda: S.One)
+        for factor, k in factors:
+            combined[k] *= factor
+        factors = sorted(combined.items(), key=lambda x: x[0])
+        factors = [(f, k) for k, f in factors]
+    return factors

Based on my understanding of the issue and the sympy codebase structure, here is the patch:

--- a/sympy/polys/polytools.py
+++ b/sympy/polys/polytools.py
@@ -6213,6 +6213,17 @@ def _symbolic_factor_list(expr, opt, method):
 
     return coeff, factors
 
+
+def _sorted_factors(factors, method):
+    """Sort factors list and combine factors with same multiplicity for sqf."""
+    if method == 'sqf':
+        # Combine factors with the same multiplicity
+        from collections import defaultdict
+        combined = defaultdict(lambda: S.One)
+        for factor, k in factors:
+            combined[k] *= factor
+        factors = [(combined[k], k) for k in sorted(combined.keys())]
+    return factors
 
 def _factor_list_syms(result, syms):
     """Return a list of factors from a symbolic factorization."""
@@ -6230,6 +6241,7 @@ def _generic_factor_list(expr, gens, args, method):
 
     try:
         coeff, factors = _symbolic_factor_list(expr, opt, method)
+        factors = _sorted_factors(factors, method)
     except PolificationFailed:
         return S.One, [(expr, 1)]