Intermittent CI failure in wallet_send.py, in , line 329, in run_test assert_fee_amount(fee, count_bytes(res["hex"]), Decimal("0.00002")), AssertionError: Fee of 0.00000438 BTC too high! (Should be 0.00000432 BTC) #36394

https://github.com/bitcoin/bitcoin/actions/runs/36761522744/job/110045003745?pr=36340#step:11:8289

 test  2026-09-30T18:59:19.594725Z TestFramework (ERROR): Unexpected exception: 
                                   Traceback (most recent call last):
                                     File "/home/runner/work/_temp/test/functional/test_framework/test_framework.py", line 145, in main
                                       self.run_test()
                                     File "/home/runner/work/_temp/build_ ₿🧪_/test/functional/wallet_send.py", line 329, in run_test
                                       assert_fee_amount(fee, count_bytes(res["hex"]), Decimal("0.00002"))
                                     File "/home/runner/work/_temp/test/functional/test_framework/util.py", line 69, in assert_fee_amount
                                       raise AssertionError("Fee of %s BTC too high! (Should be %s BTC)" % (str(fee), str(target_fee)))
                                   AssertionError: Fee of 0.00000438 BTC too high! (Should be 0.00000432 BTC)

Originally posted by @maflcko in #36340 (comment)

The signature in this run was 3 bytes shorter than the 71 bytes the wallet assumes, because of leading zeros in r or s (about 1 in 4 million). The wallet paid for 219 vbytes (Fee:438 Bytes:219 in the node log) and the transaction was 216, one byte more than assert_fee_amount allows. #36408 raises the allowance to 3 bytes.