Cannot create an LP on Celo

Bug Description
Cannot approve or add liquidity for this specific token (https://celoscan.io/address/0xcde66143c5d9b134daba0e6a96e476b1bd347b04#code). Is there an issue with the token not conforming to a specific interface?

index.ts:269  Uncaught (in promise) Error: cannot estimate gas; transaction may fail or may require manual gas limit [ See: https://links.ethers.org/v5-errors-UNPREDICTABLE_GAS_LIMIT ] (reason="execution reverted: ZERO_FIRST", method="estimateGas", transaction={"from":"0x5523058cdFfe5F3c1EaDADD5015E55C6E00fb439","to":"0xcde66143C5D9B134DabA0e6A96e476b1bD347B04","data":"0x095ea7b30000000000000000000000003d79edaabc0eab6f08ed885c05fc0b014290d95a0000000000000000000000000000000000000000000000000000000005f5e100","accessList":null}, error={"code":-32603,"message":"Internal JSON-RPC error.","data":{"code":3,"message":"execution reverted: ZERO_FIRST","data":"0x08c379a00000000000000000000000000000000000000000000000000000000000000020000000000000000000000000000000000000000000000000000000000000000a5a45524f5f464952535400000000000000000000000000000000000000000000"},"stack":"{\n  \"code\": -32603,\n  \"message\": \"Internal JSON-RPC error.\",\n  \"data\": {\n    \"code\": 3,\n    \"message\": \"execution reverted: ZERO_FIRST\",\n    \"data\": \"0x08c379a00000000000000000000000000000000000000000000000000000000000000020000000000000000000000000000000000000000000000000000000000000000a5a45524f5f464952535400000000000000000000000000000000000000000000\"\n  },\n  \"stack\": \"Error: Internal JSON-RPC error.\\n    at new n (chrome-extension://ejbalbakoplchlghecdalmeeeajnimhm/common-2.js:16:22333)\\n    at s (chrome-extension://ejbalbakoplchlghecdalmeeeajnimhm/common-2.js:16:26272)\\n    at Object.internal (chrome-extension://ejbalbakoplchlghecdalmeeeajnimhm/common-2.js:16:26882)\\n    at c (chrome-extension://ejbalbakoplchlghecdalmeeeajnimhm/background-0.js:7:44209)\\n    at chrome-extension://ejbalbakoplchlghecdalmeeeajnimhm/background-0.js:7:45208\\n    at async chrome-extension://ejbalbakoplchlghecdalmeeeajnimhm/background-4.js:12:54199\"\n}\n  at new n (chrome-extension://ejbalbakoplchlghecdalmeeeajnimhm/common-2.js:16:22333)\n  at s (chrome-extension://ejbalbakoplchlghecdalmeeeajnimhm/common-2.js:16:26272)\n  at Object.internal (chrome-extension://ejbalbakoplchlghecdalmeeeajnimhm/common-2.js:16:26882)\n  at c (chrome-extension://ejbalbakoplchlghecdalmeeeajnimhm/background-0.js:7:44209)\n  at chrome-extension://ejbalbakoplchlghecdalmeeeajnimhm/background-0.js:7:45208\n  at async chrome-extension://ejbalbakoplchlghecdalmeeeajnimhm/background-4.js:12:54199"}, code=UNPREDICTABLE_GAS_LIMIT, version=providers/5.7.2)
    at p.makeError (index.ts:269:28)
    at p.throwError (index.ts:281:20)
    at v (json-rpc-provider.ts:78:20)
    at ef.<anonymous> (json-rpc-provider.ts:642:20)
    at Generator.throw (<anonymous>)
    at a (674.588248c5.js:27:226741)

Steps to Reproduce

1. Go to Add Liquidity
2. 1% fee tier
3. Set price range, low=1, high=2
4. Starting price = 1
5. Deposit amount 100 SRFTEST
6. Approval fails
   ...

Expected Behavior

Should be able to create an LP.

Additional Context

The token contract itself is a demurrage token (The balance of users gradually decays). We do not use external erc20 libraries like OpenZepplin. The source has been published (link above).

Start with the Add Liquidity flow described in the reproduction steps and trace the approval transaction that reverts with ZERO_FIRST. Compare how this demurrage token behaves with the interface’s approval assumptions. Done means the token can be approved and used to create an LP, with coverage for the observed failure if the project supports it.