Hi,

    In odoo 14, if you check the account_move.py , they have set tracking is true for Untaxed amount

amount_untaxed = fields.Monetary(string='Untaxed Amount', store=True, readonly=True, tracking=True, compute='_compute_amount')

You can set tracking = False by inheriting account.move class and make sure you inherit the compute function too.

class AccountMove(models.Model):

    _inherit = "account.move"

    amount_untaxed = fields.Monetary(string='Untaxed Amount', store=True, readonly=True, tracking=False, compute='_compute_amount')