Is there a limit of 100 characters in line_items custom_fileds ?

Is there a limit of 100 characters in line_items custom_fileds ?

When I'm trying to add custom_fields information for line_items (when creating estimate) I get this error whenever the data is bit too long: Please ensure that the custom_fields has less than 100 characters. 

This seems extremely weird as I don't have this limitation when adding custom_fields when creating items or for invoice/estimate custom fields. This is the data I'm sending:

  1. {
  2.   method: 'POST',
  3.   headers: {
  4.     Authorization: 'Zoho-oauthtoken 1000.xxx.xxx'
  5.   },
  6.   body: '{"customer_id":"268705000000342676","salesperson_name":"xxx xxx","date":"2018-07-15","estimate_number":"xxx","custom_fields":[{"label":"Notes","value":""},{"label":"Description","value":"xxx"},{"label":"Metadata","value":"{}"},{"label":"Prepayment percent","value":0},{"label":"Type","value":"Pavadzīme"}],"line_items":[{"item_id":"268705000000456283","tax_id":"268705000000039115","quantity":60,"rate":8.4105,"custom_fields":[{"label":"Metadata","value":"0123456789001234567890012345678900123456789001234567890012345678900123456789001234567890"}]},{"item_id":"268705000000454211","tax_id":"268705000000039115","quantity":6,"rate":63.95,"custom_fields":[{"label":"Metadata","value":"0123456789001234567890012345678900123456789001234567890012345678900123456789001234567890"}]}]}'
  7. }