New model added via Studio causes a KeyError on a computed field - odoo

Question

[Odoo v13 cloud edition]
I've added a new model via Studio: crm.lead.activities. In that model I have a computed field x_name:
Dependencies: x_res_id, x_date, x_activity_type_id
Compute:
for record in self:
record['x_name'] = record.x_res_id.name + ' / ' + str(record.x_date) + ' / ' + record.x_activity_type_id.name
x_res_id is a many2one field to crm.lead
But when I try to (un)install a module, I get a KeyError. What can I do to solve this?
Odoo Server Error
Traceback (most recent call last):
File "/home/odoo/src/odoo/13.0/odoo/http.py", line 624, in _handle_exception
return super(JsonRequest, self)._handle_exception(exception)
File "/home/odoo/src/odoo/13.0/odoo/http.py", line 310, in _handle_exception
raise pycompat.reraise(type(exception), exception, sys.exc_info()[2])
File "/home/odoo/src/odoo/13.0/odoo/tools/pycompat.py", line 14, in reraise
raise value
File "/home/odoo/src/odoo/13.0/odoo/http.py", line 669, in dispatch
result = self._call_function(**self.params)
File "/home/odoo/src/odoo/13.0/odoo/http.py", line 350, in _call_function
return checked_call(self.db, *args, **kwargs)
File "/home/odoo/src/odoo/13.0/odoo/service/model.py", line 94, in wrapper
return f(dbname, *args, **kwargs)
File "/home/odoo/src/odoo/13.0/odoo/http.py", line 339, in checked_call
result = self.endpoint(*a, **kw)
File "/home/odoo/src/odoo/13.0/odoo/http.py", line 915, in __call__
return self.method(*args, **kw)
File "/home/odoo/src/odoo/13.0/odoo/http.py", line 515, in response_wrap
response = f(*args, **kw)
File "/home/odoo/src/odoo/13.0/addons/web/controllers/main.py", line 1326, in call_button
action = self._call_kw(model, method, args, kwargs)
File "/home/odoo/src/odoo/13.0/addons/web/controllers/main.py", line 1314, in _call_kw
return call_kw(request.env[model], method, args, kwargs)
File "/home/odoo/src/odoo/13.0/odoo/api.py", line 387, in call_kw
result = _call_kw_multi(method, model, args, kwargs)
File "/home/odoo/src/odoo/13.0/odoo/api.py", line 374, in _call_kw_multi
result = method(recs, *args, **kwargs)
File "<decorator-gen-66>", line 2, in button_immediate_upgrade
File "/home/odoo/src/odoo/13.0/odoo/addons/base/models/ir_module.py", line 72, in check_and_log
return method(self, *args, **kwargs)
File "/home/odoo/src/odoo/13.0/odoo/addons/base/models/ir_module.py", line 634, in button_immediate_upgrade
return self._button_immediate_function(type(self).button_upgrade)
File "/home/odoo/src/custom/trial/saas_trial/models/module.py", line 99, in _button_immediate_function
res = super(IrModuleModule, self)._button_immediate_function(function)
File "/home/odoo/src/odoo/13.0/odoo/addons/base/models/ir_module.py", line 573, in _button_immediate_function
modules.registry.Registry.new(self._cr.dbname, update_module=True)
File "/home/odoo/src/odoo/13.0/odoo/modules/registry.py", line 86, in new
odoo.modules.load_modules(registry._db, force_demo, status, update_module)
File "/home/odoo/src/odoo/13.0/odoo/modules/loading.py", line 369, in load_modules
registry.setup_models(cr)
File "/home/odoo/src/odoo/13.0/odoo/modules/registry.py", line 290, in setup_models
for path in transitive_dependencies(field):
File "/home/odoo/src/odoo/13.0/odoo/modules/registry.py", line 276, in transitive_dependencies
for seq2 in transitive_dependencies(seq1[-1], seen + [field]):
File "/home/odoo/src/odoo/13.0/odoo/modules/registry.py", line 272, in transitive_dependencies
for seq1 in dependencies[field]:
KeyError: x_crm.lead.activities.x_name